Scanning your link,

It seems like the majority of the non-Facebook figure comes from Chinese language sites. Since social networking sites will quite likely be segmented by language for the foreseeable future, I don't think this really counts. In the English-language world, Facebook has serious network effect and you would be hard-pressed to combine all of FB's competitors into anything.

I agree dispersed social networking is coming... I'm not sure if "control" of data is the way to phrase the "problem"... Still, creating a dispersed network where each contributor controls where their data goes is a very hard problem.