Well, here comes MySpace which, like Google, has the clout to give these guys a run for their money. Here’s the activation page for MySpace’s IM, though it doesn’t seem to be working for us yet, and same seems to be true for others (see comments).
Let’s face it, though. IM is now a commodity. The only drag for open IM communications are the walled gardens built by AOL, Yahoo and Microsoft. As others — Meebo, Google, etc — push open standards, the majors will be slowly forced to adapt.