Official artwork from Marvel vs. Capcom 3. I am not entirely sure who the other characters are as they are not revealed yet. Chun-Li and Felicia are a sure bet though, as is Captain America.
I don't know if the guy on the far right (right under Chris' gun) is either Frank West or Chuck Greene, and I can't tell if the person behind Chun-Li is either Deadpool or Blade. Also I don't know if the guy with the sword beneath Chris' chin is either Dante or Nero, could be either guy.
Something like this.. Left of Morrigan: Super Skrull. Under Super Skrull: Mephisto. Under Memphisto: Black Widow Under Black Widow: Deadpool Under Deadpool: Chunli.
Right of Chris: Doom Under Ant man: Dante Under and to the right of Dante:Frank West Under Frank West: Captain America Left to Captain America: Felicia