Metallica's website yesterday posted the following message :

"You've been posting and chatting about it for months and we're here now to confirm it . . . Metallica, Slayer, Megadeth, and Anthrax will all share the same stage for the first time EVER! Look for the four of us at the Sonisphere shows in Warsaw, Poland and Prague, Czech Republic on June 16 and 19, 2010, with a few more of the festival dates still in the works. You can be sure these shows won't be the only ones."