Read Write Web has an interesting article on chat integration: Why IM Interoperability May Just be a Dream:
Interoperability between instant messaging (IM) clients is something a lot of users have wished for. More specifically, we wish it was standard and provided right out of the box instead of having to turn to third parties such as Adium, Digsby, Trillian, or Pidgin. Yet there seems to be a problem with the concept of interoperability for the companies of the more popular IM clients.
I'm wondering how much the interoperability really matters with the growth of XMPP services through Google and Facebook? I'm personally seeing more and more people who I used to chat with via AIM making themselves available through Google Talk. How about the rest of you, are you seeing your peeps move away from AIM? Maybe interoperability just doesn't matter because we finally have a critical mass of people using XMPP-based services.