Okay... First of all I'm just going to point out that I am a hardcore Batman fan, so anyone who says differently can delete that comment right now.
Anyways. Why does everyone keep asking about prep time? And why has the topic of this board morphed into "Would Batman survive a fight with Marvel heroes"? Nobody cares if Thor would pwn Batman's ass. The question was whether or not Batman would survive in the Marvel universe. And I think he might be able to, as long as he stuck with the other heroes. If he worked together with Spidey and Cap he'd be just fine, I think. But if he decided to go off on his own, there's no way he'd survive long. The fact of the matter is BATMAN IS HUMAN. He has no powers, he has no prolonged life (yes I realize he recently "came back from the dead" but that has nothing to do with him having any kind of powers), he has nothing but his intellect and therefore his gadgets to save him. And granted, those will get him far because he is very intelligent and extremely good at solving problems and figuring out how to best his foes. But he doesn't have to figure out how to beat superhuman villains very often, does he? He needs TIME (yes, that prep time everyone is so fond of talking about) to construct a plan to overcome his enemies, especially when they aren't just regular humans, and that TIME that he needs just might get him killed if Electro starts aiming lightning bolts at his face.