Frontman says veterans will become 'a singles band'
They head towards third decade with marathon show
'If All Goes Wrong' is out in December
'If All Goes Wrong' will screen for one day only on November 6
There will be unique sets every night
Concert film and documentary mark band's 20th anniversary
Plus players will be able to play as Billy Corgan
It'll take place August 22 at the Hard Rock
Smashing Pumpkins frontman seeks $100,000 in damages
James Iha and D'Arcy Wretzky-Brown file suit