RB2 works with GHWT, RR peripherals
But only on PS3 for the moment.
Harmonix has patched Rock Band 2 on PS3 to support Guitar Hero World Tour and Rock Revolution peripherals.
An Xbox 360 update is "forthcoming", according to the Rock Band forum.
"Consumers should not be forced to buy separate controllers for each game. Rock Band peripherals should be compatible with other music games - even those of our competitors," said the developer.
"We are extremely excited that consumers can finally use the peripherals of their choice with their games on the PS3, and that they no longer need to buy multiple guitars or drums."
There's a few other bug fixes in the PS3 patch, and full notes can be found on the Rock Band forum.
Previously, both Sony and Microsoft have aired plans to make instruments from Guitar Hero World Tour, Rock Band 2 and Rock Revolution cross-compatible on their respective formats.