I haven't had an invite yet.
It looks cool. Nothing groundbreaking, but some substantially well through through UI tweaks to existing ideas (Dreamwidth users are probably pointing at the "Circles" idea and going "ours" quite a bit, whereas G+ is laughing at the management interface...)
ETA: I know have an account, and it is good-never actually received an invite, I just got in via a link, weird.
Mat Bowles - Google+