Hey hey, what's this? Not only is Activision CEO Bobby Kotick quoted in this month's Conde Nast Portfolio saying that future versions of Guitar Hero will have "other instruments" and "vocals," but our crew over at Joystiq says that a source within Activision has confirmed that Guitar Hero IV will feature a microphone and drumkit, and that Activision is planning on pumping out new downloadable content as often as "weekly" once Guitar Hero: Aerosmith comes out in June. These aren't particularly surprising developments, considering how well Rock Band went over, but here's hoping Activision and Harmonix can set aside their differences at least long enough to make those drumkits compatible -- as anyone with Rock Band knows, they don't exactly disappear in a living room.

Read - Interview with Activision CEO Bobby Kotick in Portfolio
Read - Joystiq post about Guitar Hero IV

D-BOX Motion Code system gets explained