MCH1:
I take it that the GH3 guitar will work fine with this?
Looks like it's definitely YES for all the 360 controllers,
This is from Wikipedia -
New instrument controllers are not required to play World Tour. Older Guitar Hero guitar controllers still work with the game.Activision stated during their press conference held alongside E3 2008 that for Xbox 360 users, the existing Rock Band instrument controllers as well as other third party controllers also work in Guitar Hero World Tour;Rock Band instruments for the PlayStation 3 are not guaranteed to work in World Tour, though Sony is attempting to help make these units compatible.