Well this was unexpected, or, as BGR put it, “hell freezes over.” AOL has released a new instant messenger client for Windows Mobile. It looks... good. Looks like we've got buddy list management, real custom status updates, and a few more bells and whistles built in. No auto-updates, though, so if you join up for this Beta be sure you check back often to get the latest builds.
Naturally, you'll want an unlimited data plan with this. Notable: doesn't appear to work especially well with the Touch soft keyboard, so don't go replacing your current IM client just yet.
It should be compatible with anything WM5 or later and it's a free bit o' software, so go on and give it a go: