I wonder if Google believes that acquiring enough social networking startups will enable them to cobble something together that competes with Facebook. I suppose it's possible, but I'm skeptical.
Probably talent acquisitions: people who already know the field, and who have demonstrated their ability to create a social network. I wouldn't describe it as cobbling, although I suppose they are cobbling a team together from lots of different groups.
It's not like a social network is a difficult thing to build. Google's got the audience, all they have to do is build something that's useful and addictive.
I think one of Google's main problems in respect to building apps, is they stick to their overly simple design principles, which don't lend themselves to complex services like social networks. If you log into Orkut as an early adopter, it's not that impressive at all. Similar experience with Wave.
