Rock Band for the Wii, despite its lack of DLC, you'll be interested to know that IGN recently took the Wii drum kit for a spin. Apparently, when Rock Band first released on the PS3 and Xbox 360, some folks were having trouble with the bass pedal (among other things), so a revision to the hardware was initiated. With the Wii drum kit, all of those changes are already in effect.
IGN says it best, though: "If you have the option, buy Rock Band for any console that's not the Wii, as you'll get the same drums (in black) and have access to downloadable content." Seriously, the Wii version isn't going to be that good, but if it's your only option, we wish you the best in rocking out and cross our fingers that Rock Band 2 isn't as lacking in the features department when it hits retail shelves.