I think it will be far superior to Facebook, as google+ integrates with all googles other features such as gmail, google voice, google chat, google music, and a twitteresque feature as well. It also allows you to divide people into as many circles as you want (friends, hoes, family, etc), only sharing information with who you want.
It is only bound to improve as time goes on and already I prefer it to facebook. There aren't that many people on it at the moment but public registration is closed. I do think you need a gmail address to sign up. I have invites. Feel free to drop me your addresses.