Believe me I have reservations on some of the choices Goog has made here (at least in what I've explored), but I think Buzz (even with that name) is trying to be more than just a public social tool. So even if you write off the Facebook/Twitterish aspects, it seems they're trying to fix certain IM/email divisions and collaboration problems. It's a simplified Wave platform (more linear and email-like) which possibly has business uses (better group IMing and archiving, etc.). With so little documentation it's not only a bit of a pain to use, it's currently an experiment in screwing over your friends security, so I hope changes get made quickly, but I'd hold off thinking it's only as Googles Twitter. Or at least hold off until it finds it niche. If it becomes mainly a public social tool those other uses may retreat (though that hasn't happened to IM). And those security mistakes don't bode well for non-public social plans. We'll see.