It works for volume control keys and Eject. I could not reproduce problems described earlier - both Terminal and arrows in iTunes work fine. If I encounter any problems - I'll update this thread.

The only key which is not working is Num Lock. It works only as Clear key - just like on the latest Apple keyboards. There is no way to cancel default "Num Lock = on" state. It's a bit confusing since Num Lock LED is actually off.

macally.com has a newer (or at least repackaged) version circa 2008. However, this version dumps debug messages to Console on each keystroke. See http://discussions.apple.com/post!reply.jspa?threadID=1993310 for more info.