Florian Jensen reports that AOL is testing ICQ and AIM interoperability using XMPP. If they adopt XMPP, AIM and ICQ should work with Google Talk as well, although they could of course prevent that from happening if they chose to do so.
I started blogging about the need for interoperability among instant messaging services years ago, but very little progress has been made. Still, this is a sign of hope.
OpenAIM
AOL has officially AIM to third party instant messaging clients under an initiative called OpenAIM 2.0. There’s now a documented API that IM client writers can use to interface with AIM. Before, software developers reverse engineered the protocol used by the official AIM client and updated their software whenever AOL made changes that cut them off.
Hopefully this is one more step toward federation among services.