Red Octane showed Joystiq their new wireless controllers coming to Xbox 360, PS3 and Wii with the release of Guitar Hero III this fall. The Wii version (seen above), allows you to put your Wiimote into it via a flap in the back. The rest of the controllers look fine and the buttons are in the perfect place so you don't "pull a Peter Moore" in GH III like you would in Rock Band.
The weird news is Red Octane's cagey attitude towards pricing between systems, the same thing Joystiq experienced with Harmonix about Rock Band...