UPDATE: The poster was confirmed as a hoax.
In regards to this poster which has been circulating on metal forums galore, organisers of Sonisphere have yet to approve or disprove the rumours. Whilst we await a reply, we thought we would have a look at the likelihood of some of the headliners actually confirming:
Iron Maiden - Set to embark on the Seventh Son Of A Seventh Tour next year, amongst the many dates confirmed, a festival date is likely to be in the mix, with internet forums and message boards pointing towards Sonisphere. Verdict: Very Likely
Pantera w/ Zakk Wylde In a recent article with SMN news, when asked "Vinnie Paul said if Pantera reformed you’d be the man to replace Dimebag Darrell." Zakk Wylde stated "I love all those guys. It would be an honor. How could I say no? I’d do my best to make them proud."
Pantera this year also celebrated the 20th anniversary re-release of Vulgar Display of Power along with a new undiscovered complete track "Piss". While rumours of a 2013 tour are being discussed, unlike Iron Maiden who have confirmed with fans that a tour will be happening, the same can't be said for Pantera. Verdict: Unlikely...for now!
Skindred The band were originally set to play the 2012 UK Sonisphere festival but were then invited to play Download once Soni was cancelled. The band have played quite a lot of festivals and tour dates this year, however given the popularity it's tough to rule them out just yet. Verdict: Quite Likely
No Doubt With a new album out, tour and festival dates could be on the cards, yet we can imagine that their setlist at Sonisphere would feature more of their earlier material, despite a deep search of the interwebz, we were unable to find further clues Verdict: Unlikely
Motley Crue On August 4th Vince Neil revealed during an interview that Mötley Crüe might release an EP rather than a tenth studio album, a tour coupled with festival slots looks like a certainty. Verdict: Likely
An interesting one not mentioned on this list, but a rumour just as strong is in regards to German metallers Rammstein, who have confirmed that the summer of 2013 will see many a European festival slot played by them.