These do not work, as of yet (please re-read that sentence once again). It appears most of these are almost final, and carrier implementation should start at some point (likely before year end). I'm going to guess that the MSN client is released first, followed by the AIM and ICQ clients (these should be released at the same time).
As seen in the screenshots, these are going to be available in the following locations (subject to change) once they are released (again, subject to carrier compatibility and exclusivity agreements):
MSN:
www.blackberry.com/msnmessenger
AIM:
www.blackberry.com/aim
ICQ:
www.blackberry.com/icq
NOTE: These are
NOT available for download, for use, or anything along those lines. Even if you had the clients loaded on your handhelds,
THEY WOULD NOT WORK! NO REQUESTS!