What is it:
GoogleBook, or MyGoogle or Googlester - Google+ is Google's attempt to control more of your data provide more social networking opportunities show more ads in your face to people worldwide.
It's still closed beta but they've revealed a bunch of vids on their approach and there's a list you can sign to find out if you ever get an invite.
So google seems to have learned from the Buzz disaster and try to flaunt with a system with a simple interface and easier limited sharing options. Google already owns your data anyways. Why not trust them? It's perfect!
You can probably expect good mobile support.