Drummer Bill Ward says it will take a "righting of the wrongs" by Ozzy Osbourne and being presented a signable contract for him to return to Black Sabbath.
Festival attendees will still get their fix of Ozzy Osbourne, as the Prince of Darkness will perform with his solo act, reportedly with some special friends.
Stone Sour will release 'Meanwhile in Burbank…', a five-song EP featuring cover songs from Black Sabbath, Metallica, KISS, Judas Priest and Alice in Chains.