What about interoperability with aim chat rooms?
That is significantly harder. Consider a graph (as in, graph data structure) of IM users. Communicating between an AIM and an XMPP user is a single line, and even though the two nodes are on different services it's not that hard to make work. Almost by definition, both services have very similar semantics for what an IM is, and stuff like presence converged a while ago enough for interop. Now, consider a conference.…
Right, that makes sense, thank you for the explanation. I guess interopertability between the two services implied to me they could speak eachothers' protocols in entirety (at least ideally), so i pictured gtalk talking to the aim chat room via its protocol. Oh well.
BTW this has implications for google apps users since there are no usable persistent chat rooms in gtalk. Well i guess any users, but for businesses chat rooms are more useful than for casual users I think.