social networks focused on entertainment will have a limited shelf life, as the tend to focus on short term attention and on teens.
Linkedin is a slightly different case. It is like a useful business directory.
The next wave will be vertical SN's.(few billion dollar ideas there), and networks with a strong mobile component.
I have started to dump all my entertainment focused social networks. I keep an account on facebook, but only use it to keep track of people. I hate their stupid applications.
More classic MM haterade fuelled ranting. keep swigging. (with credit to aston)
But I like the article a lot. Facebook now feels like the warm up to something greater. (and probably smaller)
The identity thing is no longer an advantage for them since they opened up beyond schools and coroporates. It is socially engineered toward real identities, but that's all.