>>88769862X-Men will be in it.
FYI the "leaker" saying they wouldn't because it was a MCU centric game was lying and it was all debunked since they also said several other things that weren't true like that the Marvel characters would all be voiced by their film actors as we know isn't true since the official trailer.
So you can relax.
>>88769665Venom, hell I'd be fine with Agent Venom actually but I don't see it happening now.
Darkhawk
X-23
Green Goblin
Moon Knight/Daredevil (Doubt both can make it in)
Ghost Rider (I'd like for him to not suck as well, but I guess I can wait for fan patches for the PC version of MvC3)