A few weeks ago, I bought a Rock Band 2 Band-set... Guitar, Drums, and Mic... for my Wii console. For reference, my Wii is a modified US version with a Wii-Key installed. My Rock Band 2 copy is of course original since it came with the bundle. I thought at first I made a bad move buying a Rock Band bundle and not a Guitar Hero instrument bundle to ensure that I could use the same instruments for the upcoming Guitar Hero 5.
Well, after "purchasing" a copy of Guitar Hero 5 (game only)... I gambled on just trying the Rock Band instruments just for kicks before I purchase a Guitar Hero guitar. Turns out, the wireless guitar and wireless drum set actually works! Cool!!!
My office-mate has a Rock Band 1 instrument bundle, I'm pretty much guessing it will also work with Guitar Hero 5... Woot!
That's about it I guess... I'm off to band session... nyahahaha!