Chat! I have!
Sweet! Chat has been enabled in my Gmail account. (Yours will come soon, really - the rollout will just take a few weeks.)
We've been using Gmail Chat internally for a while now and I rely on it completely. I was surprised to find that my IM usage within a browser, previously dormant, became commonplace as well as becoming my default messaging environment. I don't suspect that'll happen to everyone, but I'm pretty curious to whom that does happen.
Dear Talk team: You are cougar. (Trying to coin a complement.)
Dear Safari users: We know. We love you. We're in progress.