We're all well aware that Spider-man 2 is coming soon (this fall) with Wolverine coming at a later date. And as much as we praise Insomniac's work, they're human and can be burned out. So if Sony looks to work on more Marvel properties, it would be best to let others in their stable take up some of that slack. Santa Monica, Sucker Punch, Naughty Dog, and Bend for example would probably make good candidates for creating other Marvel games. 

Sucker Punch seems like the most obvious bet based on their history with InFamous.

Though I reckon most of their teams wouldn't have any problem doing a superhero based game if they wanted.

I personally felt that Sucker Punch would be the best for for an X-men game

Platinum Games - Deadpool
Rockstar Studios (particularly the ones that made Max Payne 3)- Punisher or Blade
Sucker Punch - Black Widow
Yakuza developers - Luke Cage

I think that's all I got.

Based on their experience w/ God of War, the Santa Monica Studio would be the perfect fit for a Thor game.

Good call, but Thor would probably feel too familiar. I get that Marvel's Thor is nothing like the actual Norse mythos Thor.  But I can't see Santa Monica doing that for the sheer idea of "been there, done that".

I really liked Marvel Ultimate Alliance 3. Not everything needs to be AAA story-driven things.

RGG studio be better for Jessica Jones. Judgment has all the DNA. Private detective and beat-up thugs.

I dont know whoever developed it, but the Spider-Man game for Gameboy was quite entertaining. =P

Capcom has quite a history with Marvel. It started already in the 90s and they made a bunch of fighting games in the meantime. Also Koei Tecmo did a fine job with Marvel Ultimate Alliance 3.