Would be really nice if there was a way to incorporate a chatroom into v3. I'm also interested in offering my members a way to establish a live IM session (outside of the chatroom), instead of always having to PM each other. For instance, they would click "IM" on their profile, and it would wait up to 3 min for the other party to accept.
Even if these two features were considered add-ons, I would definitely pay for them.