Since this thread was started their have been some new developments in the Facebook story:
- Facebook opened up as a developer platform for third-party apps
- Microsoft invested $240M in Facebook for about a 2% stake in the company ($15B valuation)
The first point changes the game significantly I think. There is quite a bit of promise in Facebook as a platform, leveraging it's social graph and you can't deny the power of the network (see Social Networking in Plain English). I've changed my position slightly from apathy to more of a curious interest in whether or not the apps thing will take off. And not just vampire or zombie apps!