The initial lineup has been revealed for next year’s Wacken Open Air festival. The event will be held in Wacken, Germany on July 29 to August 1 and it will feature the following: Def Leppard, Powerwolf, In Flames, Savatage, Runningwild (final show), Emperor, Sepultura (final German show), Lamb Of God, Airbourne, Europe, Blood Fire Death:…