Google has come out with what Brent actually envisioned for the BlogChat webchat application in 2001/2002. He wanted visitors to his website to be able to chat with him but not necessarily give out his IM address etc. The Google Chat Widget is basically that and ties into GTalk (Google IM) without revealing one's actual IM address etc. However, it is only one-to-one so no group chat available at this time (perhaps they'll add that as a feature).

Very nice though.