The new issue of Game Informer Magazine has the scoop, reported by a poster on the NeoGAF forum and picked up by Kotaku: Guitar Hero IV will feature drumming and vocals. What an original idea!

To be totally fair, it does seem like a logical next step, and it's not like Harmonix invented the idea, either.

WORLD RENOWNED RECORDING GROUP AEROSMITH ROCKS THIS WAY TO GUITAR HERO®: AEROSMITH®
Epic Collaboration Creates First Music-Based Game to Feature One Band

Santa Monica, CA – February 15, 2008 – Fire up the fret board, crank the amp to 11 and get ready to rock this way with Activision, Inc.

Start putting out heartland-ish rock and you're bound to attract an audience partially made up of drunken brodudes. That’s the lesson to take from former D Generation frontman-turned-roots-rocker Jesse Malin’s show last night at TT’s, during which it was hard to tell if the group in the center of the room yelling out over a few of the singer's acoustic numbers and his occasionally verbose song introductions were disciples or haters.