I love music games, but Rock Band 2 and Guitar Hero World Tour offend me on an environmental level. Games that come in boxes so big you can't carry them in a backpack shouldn't be allowed to come out every year. It's just completely not cool. It's the same with iPhones and iPods. I love the improvements they are able to make so quickly, but it's so wrong to expect, tempt, or even want people to buy new versions of perfectly good stuff every year or even every other year (for particularly expensive items). I know that you don't have to buy the new peripherals or upgraded versions, and I guess I'm hoping that most people don't. But I'll be the first to admit that it's hard to play with my old crappy Rock Band 1 drums when I know the new kit has so many needed improvements (quieter pads, mainly, but also the better attachment for the pedal so it doesn't fall off so easily). If the better drums didn't exist until two or three years from now, though, I'd probably feel perfectly satisfied with my old ones. What would be so bad for them if they just put out new drums every few years and rolled all the upgrades into the rarer, better versions? I suppose that's just completely at odds with our consumer culture though.... There's this longish but really well done little video about this problem called The Story of Stuff.
At least USB as a standard means the controllers are compatible with the different franchises. Proprietary controllers would simply be unacceptable.