Cable, the mutant with the amazing power to have a gun (he has other powers, but the gun one is the standby), appears in Marvel Ultimate Alliance 2 as an NPC, but the latest announced downloadable content for the game adds him as a playable character. Soon, you'll be able to have a big futuristic space-gun in the game as well! Activision didn't specify a time frame for this DLC. It's just "upcoming."
Video game fans might know Cable best as one of the cheapest characters in Marvel vs. Capcom 2. For the sake of this game, let's hope he's a bit less powerful now.