I had really thought about buying this for Rock Band, but when I have to consider that I'll have to pay more for Pro tracks for all of the songs (that I already bought) and would actually like to play with it, rather than the songs that come with the game that have Pro support, it's kind of a hard pill to swallow.
Plus, there is a part of me that would rather have Bass Pro support. Playing the bass just seems like so much more fun for some of the songs. Probably just me though.