So I guess the cat got out of the bag a little early. I tried it out with iChat (hit command-3 to bring up jabber and configure) and got right in with the details at that link.
I just realized something. I use Google for searching with my personal history turned on, and I view it through my personal portal, and I get all my personal mail through Gmail, and everything I've said online for the past ten years is available within Google's index, and now all my daily chitter-chatter could be on a Google server as well.
They don't do evil, but still, it's something to think about.