has posted information on Harmonix's Rock Band that purportedly came from the latest issue of Game Informer. The article goes into some detail about the instrument controllers, including the guitar, drums and microphone.
According to the post, the guitar/bass controller in Rock Band will feature ten buttons -- five at the top of the neck and five near the body. The new buttons will be used during designated solo sections using only hammer-ons and pull-offs (i.e. no strumming). A five-way switch will let you switch between special effects that you can purchase in-game. The Xplorer 360 guitars will still reportedly work with the game, however.
The microphone is said to work as a tambourine for parts of a song where no vocals are present, and a phoneme detector is meant to judge whether or not you're singing close to the right words. The drums are described as a set of four colored pads with a stand and a kick pedal, ready to be struck with real drum sticks. Also listed in the NeoGAF post are details on how multiplayer will work and descriptions of the in-progress visuals. If that's music to your ears, you might want to go and suggest some songs to be included in the final game at Rock Band's website.