Four new bands have been confirmed to be playing @Metalcamp 2012: American masters TESTAMENT, Dutch symphonic metal band EPICA (promoting their upcoming new album Requiem For The Indifferent), the brute legion of deathers a.k.a. NILE & NAPALM DEATH (playing live songs from their soon to come 14th release Utilitarian)! More info here
So far these bands have been confirmed:
THE BLACK DAHLIA MURDER
+ many more!