Gamespot released a little Q&A with Red Octane's cofounder about Guitar Hero 3's downloadable content, the acquisition of licenses and a little Drum Hero information!
It's interesting that they have been trying to get the licenses for AC/DC, Led Zeppelin, Metallica, and Van Halen for some time. To a low-on-the-totem-pole consumer like me, I was unaware that they were even trying, although I was hopeful. So to all the nay sayers, they're working on it, and the co-founder states that they have been trying for a long long time.
Check it out on EBgames.com