Back at E3 the folks from Neversoft announced that Guitar Hero: World Tour on the Xbox 360 would be completely compatible with Rock Band instruments, but weren't able to comment on compatibility for other versions of the game - until now. During the Activision press conference today at Games Convention, Neversoft's Brian Bright announced that not only would the PS3 version work with Rock Band instruments, so indeed would the PS2 version.
Later I asked Brian how exactly the drums would work, considering the original Rock Band set has four pads and a pedal versus World Tour's three drums, two cymbals, and pedal setup. Turns out that the orange pad - the crash cymbal dealie - will map to the blue pad, unless a note is already there, in which case it maps to the green on the fly. Complicated, but if it means I only need one drum set I am willing to give it a go.