problem is that facebook doesn't really have too much of an incentive to care about these developers. they are not like apple, whose products include third party apps as part of the core value proposition. when steve jobs sells you an iphone, one big reason you buy it is because it has thousands of great apps. people don't sign up for facebook because of farmville, farmville uses facebook because people have already signed up for facebook.

thus, when apple's developers get screwed and there's no app ecosystem, there is the potential for decreased sales. when facebook apps disappear, i doubt there are a lot of people leaving facebook.