Excellent move by AIM. Most notably:

“AOL is saying they’ll soon be giving partners who build software on top of AIM the option to run AOL-served advertisements with a revenue share.”

This is the future of open applications; the value must be painfully obvious to potential developers.

In my opinion this is a real oppotunity for Yahoo! to sweep in and capture the IM market entirely (at least in the US). Given a pure client to client battle Yahoo! will conquer, their client experience is just superior to the others out there, MSN is probably 2nd.