I don't think it'll be split-screen OR taking turns. It'll be two people sharing the same screen, dishing up bloody, pulpy justice to endless waves of faceless bad guys, just like all multiplayer brawlers ever 
Double Dragon
Final Fight
Battletoads
Ninja Turtles
Castle Crashers
Need I say more?
Could I trouble you for some maple syrup to go with the plate of roffles you just served up?
Tag, courtesy of fkusumot: "Why do most of the PS3 fanboys have avatars that looks totally pissed?"
"Ok, girl's trapped in the elevator, and the power's off. I swear, if a zombie comes around the next corner..."