LinkedIn is for business contacts. Facebook is for connecting with classmates and friends from days gone by. Twitter is for news. What is Foursquare for? And then what is Facebook's checkin service for? I mean, when it all shakes out. It can be hard to forsee.I find it always interesting that intelligent people like Dave care so much about current incumbents/silos in the social networking game.
For me it's self-evident that sooner than later control of social connections will be where it belongs - with the people.
For me, all these evil silos are just an artefact of a still illiquid market.