Let's assume facebook stays the basic social networking layer but most of the time people spend, and most of the data they give will be inside facebook apps. no

Let's assume facebook stays the basic social networking layer but most of the time people spend, and most of the data they give will be inside facebook apps. not so good for facebook. Zynga/farmville is a great example of such process. I'm not sure that one application will replace facebook, probably few/many games and virtual worlds.