The remote also controls the CD Player and FM Radio applications, though support for the FM Radio app may be limited. I don't recall if it changes channels or not. No other applications work with the remote control.
It would be really darn cool if some hacker could find where the remote is implemented on the system level and tap into it to extend the functionality to other applications like iTunes, though. Of course, Apple doesn't document this information for developers...
Peace,
Drew