Guitar Hero II's associate producer Ted Lange has told IGN that the developer plans to release a wireless controller for the Xbox 360 version "rather shortly".
Apparently he said that a wire is currently needed to make it work. Seeing as though we can send men to the moon, surly a wireless X-plorer isn't totally out of the question.
Lange also promised that the 360 game will feature the most downloadable content "anyone has ever seen in a game to this date." Fingers crossed we won't have to pay for it all though. If we did, you'd probably beable to buy a real guitar and amp for cheaper.
Guitar Hero II on Xbox 360 should be available around April.