I wonder how many of you actually play... But Cable, Gambit, and Psylocke, three of the best X-Men in the games series got cut out for a bunch of nonsensical Avengers, most of which never get used if you play online, at tournaments or watch on YouTube.
I'd love to see Magik, her skill set would play nicely into the game. I never saw the point in having X23 and Wolverine, they were slightly different (X being much faster, different move set and less HP) but most people just use Wolverine. It'd be like having M and Rogue. Pointless waste of data.
I can see Madrox' dupes being used like Gorgon's (from Killer Instinct) minions, except with more direct movement. Copies running around the screen adding to combo strings as they come in contact. Bishop might interesting too. Absorbing projectile damage and channeling into his meter for offense. So the more you hurt him, the bigger threat he becomes, but looses meter as he fires energy blasts that range in intensity as he uses it. Big effects need a downside. Got to have a big gun too as an option instead of the energy blasts. You may have to pick between him and Cable. I doubt they'll use both.
They will have a good amount of X-Men, if the last few months are any sign. Pearlmutter, the man in charge of this stuff seems to be open to more X-Men merchandise these days. We'll probably see 50/50 in terms of MU/X-Men roster split.