I haven't watched the videos yet. Scoble is always a little late to the game. I've never really seen him say anything too profound. And this actually verges on the sensational. I don't think techmeme, facebook and mahalo will beat google. Although, they are all piece of a more useful interweb.
But, I agree with the theory: The most important variable in the future-perfect search algorithm is 'what mom thinks'. Or more broadly: what the people you trust think is important.
If you want to know what implicit social networking is, it's best embodied in the Robot Coop's applications, where "things" mediate our connections; where common experiences and dreams connect us.