I saw some footage of it on IGN, the game looks TERRIBLE. The music that was chosen in the game sounded really weak, and there didn't seem to be any actual effect for hitting/missing the notes, the music just kept playing :| I think in theory the idea of public domain rock covers could work (imagine a heavy metal cover of Moonlight Sonata or Ride of the Valkyries!) but it sounded really bland, whatever song it was that I heard.
I honestly would like Sega to actually take this over and do a much better game, they could afford some licensed tracks for one thing, and also get some classic HOTD tunes in there.