I agree that I can not see everyone going to a single social networking model. I see different tools for different needs. I used linked in for managing professional contacts. Facebook is a more social less task oriented environment. When I look through my future seeing glasses, I see several large networks with different purposes -- all controlled by the users, not the developers. And all letting the users chose which information they share and who they receive information from (a spamless world) .. wouldn't that be nice!