while i agree that google will eventually try to bring this all together, i don't at all believe there's a) a masterplan or b) reason to get excited about it. there's been considerable hypothesizing as to why google does all this, but I really don't think they have a grand scheme outside of wisely keeping their hands in everything in case something becomes the next big money maker.
and truth is, only a couple of those in your list of google's arsenal are the best at what they do. the future is, at least i hope, in open sourcing and not having a central repository for your networking.
at some point, all this socializing on the internet becomes too much... but that's another conversation altogether.