There once was a time that Black Sabbath legend Ronnie James Dio was included amongst the list of guest stars appearing in Brutal Legend. That time has passed. But don't worry. You should see who's replacing him.
While no official reason was given for the move, it may have something to do with this lawsuit, brought by Ozzy Osbourne against former guitarist Tony Iommi. The suit sees Ozzy trying to reclaim a stake in the "Black Sabbath" trademark, and since Ozzy is also due to appear in Brutal Legend, it appears that legally that town may have only been big enough for one Black Sabbath vocalist.
Whatever. It's a shame Dio's out, but his replacement in the game is none other than Tim Curry. Yes. Tim. Curry. Who may not be "metal", but who is "Tim Curry". So, rather than mourn the passing of Dio's contribution, let's instead celebrate the fact we've got another game featuring, yes, Tim Curry!