Over 350,000 units sold in three weeks ... on a handheld? You're damn straight Activision is already booking a second tour -- call it: Guitar Hero: On Tour Decades. The sequel to last month's (yeah, last month's!) palm-packed jam session was confirmed today during the Nintendo E3 2008 keynote. While not detailed, Decades will likely include a setlist that ranges multiple ... decades. The game will also include a song-sharing feature, allowing those with only the original On Tour to sample the Decades tracks. And apparently, there could be some form of microphone functionality (karaoke?) -- as if On Tour wasn't already awkward enough to play during the morning commute...