They should have a band that actually plays music that is relevant to the games or the theme of the event, such as Dragonforce. If the band they choose plays music that is whining about a girlfriend leaving, I'm going to be very disappointed.
While I love rock in all its various incarnations as much as the next person, I think since Blizzard is in the business of video games they should reflect it in the concert choice! To that end, I nominate the following video game music artists:
Elite Tauren Chieftains Critical Hit Video Game Orchestra Video Games Live Powerglove The Protomen
I'm sure there are others out there I don't know about. Alternatively, how about an OC ReMix dance party with a good DJ? Or live band karaoke, or live Rock Band? Maybe they need to rethink the concert paradigm altogether!
i would love to see 2 of the talent contest finalist this year at blizzcon Have No Fear and song hammer i heard they were working on a awsome rock rap collab horde vs alliance song that will blow our minds song hammer is awesome and hnf brought something we have never seen id love to see actual acts that make music about the game and are from the community preform again!