The redesign is built around a new "stream" of status updates. It closely mimics the "timeline" feature of Twitter, a much smaller service which, like Facebook user, allows people to post short messages which are then broadcast to friends. But in adopting Twitter's simplified look, Facebook threw out or hid a whole host of features users have grown used to. (Try finding upcoming events, for example, or looking for updates on new friends people have made.)

A Facebook application built to poll users on the design is running 94 percent against the new design, with some 716,000 "no" votes against 44,000 "yes" votes.

One might argue that Zuckerberg didn't do the design to please the lowest common denominator of users, but instead was trying to win over the cognoscenti of Silicon Valley, who have been buzzing nonstop about Twitter. If so, he missed that target badly, too.

Facebook has a special program called "Great Apps" to recognize the best third-party add-ons to the social-networking sites. The favored few include iLike, a music app, and Causes, an app built by a startup called Project Agape which helps people rally their friends to various social issues.

Both have close ties to Facebook: Marc Bodnick, an influential Valley investor who sits on iLike's board, is the brother-in-law of Facebook COO Sheryl Sandberg. Project Agape is backed by former Facebook president Sean Parker, who still owns an estimated 5 percent stake in the company.

But guess who's been dissing Facebook's redesign on Facebook? iLike CEO Ali Partovi and Project Agape's Joe Green. Green recently wrote:

The stream does not out-Twitter Twitter and under-Facebooks Facebook.

Partovi snarkily noted that the new design inspired him to join Twitter — and employees at Slide, another Facebook-app maker, applauded his wit:

And mind you, these are people who make a living off Facebook. If they hate it, what friends will Zuckerberg have left?

By the numbers, there are no signs of Facebook fatigue. The social network's ranks swelled from 100 million in August to 120 million in October. If it sustains that improbable pace, it will encompass the entire world's population by 2012.

There's a threat to Facebook's dominance — and it's not the one you'd think. Privacy is the bugaboo everyone brings up. The company has launched a new program, Facebook Connect, which links other websites into Facebook's News Feed, the site's tattletale compendium of their friends' online activities. Connect, which is profiled in today's Times, is similar in some ways to Beacon, a feature which outraged privacy activists around this time last year when it revealed Facebook users' holiday purchases. But Beacon proved a short-lived Grinch; Facebook rapidly modified the program, and the protests died down.

If anything, the complaint users have about Facebook is not that the site shares their private details, but that their so-called friends do. A surfeit of information has led some to cull their friends' lists on the site. That's more than fine with Facebook CEO Mark Zuckerberg, who has always sought to have his site reflect real-world relationships.

Facebook's trust problem isn't with users; it's with the Web publishers and application developers Facebook executives are trying so desperately to court. And this is a serious problem, because they're the people on which Facebook is trying to build a next-generation advertising business.

By developing Facebook apps — if you've thrown a sheep or been bitten by a zombie on Facebook, you'ved used one of these — or signing up with Connect, these companies are essentially advertising on Facebook. They're just doing it subtly, through the News Feed — and sometimes the advertisement is simply for their own service. The medium is new, but the intent is the same as any other advertiser's: To interrupt users and grab their attention.

Which makes Facebook Connect's lack of progress curious. The company has signed up some minor players — among online-video sites, Hulu but not YouTube; for city guides, CitySearch but not Yelp; the San Francisco Chronicle but not The New York Times; and so on. By far the biggest omission, though, are the makers of Facebook apps.

When Facebook allowed outsiders to write applications for its site last year, companies like Slide, RockYou, iLike, and Flixster eagerly signed up; the largest Facebook-app developers raised hundreds of millions of dollars on the promise that they could piggyback on the Facebook phenomenon. But then came the zombies.

Apps which let you, say, bite your friends and turn them into werewolves provided mindless entertainment to some and annoyance to others proliferated; clever developers figured out ways to get users to spam their friends to get them to sign up for the app, too. The abuses proliferated — and Facebook's growth slowed measurably.

So Facebook cracked down on the application developers — unfairly and arbitrarily, some say. iLike, a music app, and Causes, an app which let users spread the word about do-gooding efforts, got special treatment, while other apps were temporarily removed from Facebook for privacy violations or spam. The image problems got so bad that Facebook, to the derision of many, appointed its top flack, Elliot Schrage, to run its platform efforts.

Those same application developers are now telling anyone who asks to take a wait-and-see attitude with Connect. The main attraction of Connect, as with the application platform before it, is placement in Facebook's News Feed. The lesson developers learned with the Facebook platform is that there are no guarantees of placement, and that the rules change too rapidly to build a solid business on it.

That's why Digg, the popular news-discussion website founded by Web 2.0 playboy Kevin Rose, is rumored to have struck a deal with Facebook that guaranteed a level of News Feed placement before it agreed to sign up with Connect. And app developers are advising other potential Facebook partners to get similar guarantees in writing.

It's a dilemma for Facebook. Zuckerberg has avoided the spam problems that doomed Friendster and hobbled MySpace; by cracking down on app developers, he's kept Facebook appealing to its users. But to keep Facebook independent and turn it into a big business, he'll have to build up a big advertising business. And inserting commercial messages into the News Feed is key to that. It's spam by another name, with an invoice attached.

Zuckerberg may be reluctant to make promises to other Connect partners precisely because his advertising salespeople are hoping to charge them for guaranteed placement. CBS, which is airing this year's Victoria's Secret lingerie show on Wednesday, has signed up with Connect, and the network is paying to make sure that people read on Facebook about their friends' plans to tune in to watch Heidi Klum. That's a harbinger of the future.

The application developers and website operators vying for Facebook users' attention might be relieved if Facebook just started explicitly charging for placement. A rate card would be easier to decipher than Facebook's obscure and constantly shifting antispam rules. But will a deluge of sponsored messages turn off users? There's no easy answer. If there were, Mark Zuckerberg might be more than a paper billionaire by now.

Here's an update for anyone who didn't get the memo: Facebook's applications "platform," a set of software tools for embedding timewasting entertainments within the social network's pages, is not a level playing field. Some applications are more equal than others. That's only become clearer since Facebook foolishly put Facebook's platform in the hands of its top flack, Washington-trained bloviator Elliot Schrage. Facebook's Great Apps program, meant to designate higher-quality applications, has become a shameful excuse for nepotism.

Awarding money on the merits is hard enough. When you mix in the need to help out your COO's brother-in-law's pet startup, or your ex-president's latest venture, it complicates matters. Is Facebook going to come out with a list of apps to fund that it's truly proud of? Or will this look more like an appropriations bill after it's made its way through Congress, larded with earmarks?

"I already have users complain that they can't find apps again on the new profile after first using them. the latest changes will make it even harder," writes one developer. Another: "Yup, this is a very intense change. And pretty useless from a user experience point of view. Hopefully they roll it back immediately or it was just a mistake."

Zynga makes its games easier to win for users who successfully spam their friends into signing up to play. See the above image for how Zynga does this with Attack, its version of world-concquering game Risk. The problem for Zynga and its new investors: The executives who run Facebook's platform don't like this kind of viral growth. In a blog post Monday, Facebook's Paul Jeffries explained:

Facebook is about empowering and connecting people through the sharing of information. That’s undermined if users who receive an invitation or other communication suspect it was sent for an ulterior motive, such as gaining points in a game.

Yesterday, Jeffries' thoughts became rules for the Facebook platform. According to Inside Facebook,

Applications are no longer allowed to “create artificial or inappropriate incentives to use Facebook features (including, for example, sending requests and adding profile boxes).

In the past few weeks, Facebook has temporarily banned apps by top widgetmakers Rock You and Slide, and has punished other popular app makers too, making it clear that widgetmakers which break Facebook's ever-changing platform rules — "crack its code," so to speak — don't get away with it anymore.

That is, unless they're announcing funding from Kleiner Perkins on a day dedicated to convincing Facebook developers that such a sweet deal could happen for them, too.

• Stay up to date with Facebook’s changes to their guidelines, especially in the Developers Wiki.
• If a rule is ambiguous, err on the conservative side. Don’t push the limits.
• Look at other apps, but be wary about borrowing.
• If Facebook has taken any action, As soon as you identify the issue, alter your code and contact Facebook to let them know.
• Focus on building highly engaging apps.
• If you feel like your app is in the clear, spend your time working on the new profile redesign!

If that's the case, Zuck needs to hurry up and buy in. Venture capital for Facebook-application startups is drying up. One way Facebook could make its hangers-on flush again would be with a payments system which allows users to buy and sell things — two activities we've heard many experts consider crucial to any economy.

VCs already were asking why should I not worry about Facebook copying [your widgets]. But it was a theoretical question. Now, it is practical and amplified. I think that Facebook has really killed the potential for investment in the platform or the attractiveness to entrepreneurs. I am unaware of a single VC investment in a Facebook app company post the new regime (Sheryl, Elliot, policy enforcement). and now this will definitely affect matters. The last two VC investments I believe were Friends For Sale and SGN [Social Gaming Network] — doubt either investor is happy nor would they do the same deal again.

If our widgetmaker source is correct, it is bad news for at least two Facebook hangers-on — Zynga, a widgetmaker and SocialMedia, an ad-network for Facebook widgetmakers. Both are trying to prove him wrong by raising a new round of financing.

A source tells us SocialMedia founder Seth Goldstein spent last week in New York trying to raise $20 million. A VC in the community confirms he's recently heard Goldstein's pitch. Goldstein himself tells us, "We're talking to investors," but he wouldn't confirm the terms.

Zynga, which in January raised $10 million in funding from Union Square Ventures, Peter Thiel, Reid Hoffman, and Bob Pittman, is said to have hired a bank in order to find more funding.

Goldstein says that those worried about worried whether Facebook's aggressive moves against Slide will stunt VC investment in startup widgetmakers should worry about top widgetmakers like Slide or its closest rival, RockYou, instead.

These guys wanted to believe there wouldn't be a long tail of apps on the Facebook platform. But Facebook wants lots of little apps relevant to lots of little groups. Two guys from Estonia will be able to beat a team of 45 top flight engineers. Facebook doesn't want three major developers taking over the platform like some kind of CBS, NBC and ABC. Top Facebook apps aren't all going to be made South of Market.

Remember, Goldstein's a Facebook bull because his business depends on it. But one way to read his comment is as a confirmation that no one — including VCs — should expect widgetmakers to turn into large media companies. There may be a future on the Facebook platform, but last year's frenzy that once led HotorNot founder James Hong to declare the Facebook platform "the new Internet"? It's over.

"Yes, we view this feature as directly competitive to a relatively small part of our Top Friends functionality," Slide's Keith Rabois told us. "A developer on any platform must expect that their popular, but simple, features will be absorbed into platform over time."

But none of this has the salesman in Rabois down. He goes on:

You can see that Top Friends has a very large number of complex features that have a complicated back-end (Awards, Visual Personality, Music, world-class skins) — we expect those will continue to be long-term strategic advantages over other large developers and the platforms themselves

The secret of social networking revealed: world-class skin! We always suspected as much.

Rival widgetmaker Slide went through similar traffic troubles a couple weeks ago when Facebook shut down its popular Top Friends app over privacy concerns. But in an earlier conversation, Slide executive Keith Rabois told us that in instead of buying up smaller apps, Slide is pursuing a different strategy:

Slide is in the business of building deeply engaging branded applications, at the same level of complexity and quality as a destination website, and is not interested in assembling a broad portfolio of light weight applications that are merely impression-drivers in an ad network.

There are policies Facebook has issued, but there is always room for interpretation - and in light of current changes, the interpretation is a lot more stringent now in contrast to before.

Facebook's probably getting strict because its preparing for a relaunch of its design in July. Or — and this pure speculation — the third-party security firm Rock You's rival Slide hired to audit its own privacy might have gotten paid a little extra to take a close look at the competition and alert Facebook to any infractions. We wouldn't put it past hypercompetitive Slide founder Max Levchin and his crafty sidekick, Keith Rabois.

Slide rival Rock You's Super Wall saw traffic plummet 70 percent in the last week. InsideFacebook's Justin Smith speculates the dip is due to "some kind of punitive action against the application" over privacy concerns by Facebook, "perhaps by restricting feed access or by lowering the application’s notification or invitation limits." Another source tells us Flixster, the widgetmaker behind the Movies app, is going through similar punishment from Facebook over privacy concerns.

• Track 1: User Experience
• Introducing the New Facebook Profile & More — Learn how to cope with us killing all the viral tricks you used to get users to add your applications.
• Integrating Facebook Connect into your Website — See how easy it is to let our users use all your features and stay on our site, as our users. We're the platform; you're the app, bitch.
• Building Great Applications on Facebook — We'll discuss guiding principles and best practices. For example: no more apps based on R.L. Stine characters.
• Design and User Experience at Facebook — Hear directly from the Facebook Design team on how we think about design and how little we think of yours.

• Track 2: Technical
• Advanced App Building — It's easy to build a simple Facebook app in a couple hours, but you'll just be embarrassing yourself and annoying our users. In this talk, learning the caching features of FBML, advanced features of FBJS, smart uses of the API, and more.
• Feed and Social Distribution — With the new Facebook profile, you won't be able to spam users into submission. Learn how to design great Feed stories!
• Building to Facebook Scale — Facebook handles hundreds of millions of requests per day. Your apps probably can't. We'll try to help you fix that.
• Made for Mobile — Mobile devices are opening up and creating new opportunities. For Apple iPhone developers. Why are you here?

• Track 3: Business
• Building a Business on Facebook / Metrics & Analytics — Learn everything about how to build a business on Facebook Platform from developers who are doing it. This way you'll believe its possible, and they'll be flattered by our attention.
• Marketing your Application on Facebook — You've developed an application. Now what? This session will cover how to trick users into thinking their friends won't like them anymore if they don't install it.
• Entrepreneurship on Facebook Platform — In this session you'll hear from industry luminaries in venture capital and seasoned, multi-company entrepreneurs who owe us favors or are living off past successes and have nothing else to do.
• fbFund: A Look Inside — Seeding Opportunity on Facebook Platform — Learn about the inner workings of fbFund and see what the grant winners are developing so you can spend all your time copying them while some developer in Austin who stayed away from this pointless gabfest actually builds something no one else saw coming.