SHMUPGurus:
It's also Activision being cash grubbers. The Rock Band instruments are fairly generic USB HID devices. I know this because I built my own MIDI Drum Set -> USB Wii adapter using a PIC18F4550 microcontroller. Adding software support for these devices has to be trivial at best, especially since Nintendo already provides USB HID software support in their IOS, as evidenced by USB keyboard support in various applications.
Yes, Harmonix didn't support the Wii standard interfaces, but there should be no excuse for not supporting the existing equipment other than to force people to buy your own.
Maynard_Tool:
People seem to be saying that the GH:WT instruments are compatible (drums included). However, with the terrible information that's coming out about this game, it's hard to be 100% sure.
