I don't think FB is going out of business anytime soon, but as time passes, I think that it's core value is more like its original vision -- i.e., a social directory. Seems like it'll become a repository of all your social contacts and your virtual passport when signing up for other sites and will cease to be the place where you spend all your time communicating with friends and discovering new things.
Sounds like you're suggesting Facebook may eventually become the next YellowPages. I could see that happening. It's mostly what I use it for anyway—remaining available to people who, since joining Facebook, seem to have forgotten I'm still reachable via phone, email, and IM.
