Mike D pointed out an article on Gamernode.com which talks about Guitar Hero 4, and has what appears to be an official blurb for the game taken from an online survey site:
Guitar Hero
In this new Guitar Hero game, join up with your
bandmates to form the ultimate super group and rock your way to the
top. Shred on lead, rhythm, or bass guitar (three options on one guitar
controller), rip on drums, or belt it out on the mic as you rock
together on the greatest classic, modern, alternative, pop, and metal
hits. 85 songs by artists including Jimi Hendrix, The Doors, Foo
Fighters, Smashing Pumpkins, Korn, System of a Down, Ozzy Osbourne,
Interpol, Muse, Tool (at least three songs and a dedicated venue), and
dozens more come together to form the coolest set list ever. You can
even play as your favorite rock star, choosing from characters like
Sting, Ozzy Osbourne, Ted Nugent, Billy Corgan, Jimi Hendrix, Travis
Barker, Hayley Williams, and Zak Wylde. If none of these are your
style, then you can create your own character, including character
construction, instrument creation, band logos, and album covers. Then
take it to a whole new level by jumping into a fully-integrated
recording studio to lay down, upload, and share custom tracks online –
for virtually unlimited rock. This game features the most authentic
instrument peripherals on the market including an all-new wireless
guitar controller with the first-ever touch-sensitive neck slide,
dedicated Star Power button, and ability to palm-mute. Also, the new
killer wireless drums have ultra-quiet pressure-sensitive pads, raised
cymbals, and are easy to set up and take down. Or, use the microphone
to become the ultimate frontman. This new Guitar Hero game lets you
rock together and rock for all.Expected Rating: T-Teen – Suitable for those ages 13 and over
No virtual Adam Jones to pick as you avater it would seem.