It worked so well for Team Fortress 2, after all. Players in Super Monday Night Combat will able to trade goodies and gear using the Steam trading system. I also mention Team Fortress 2 because SMNC players can pick up TF2 costumes, and Team Fortress players can earn Super Monday Night Combat hats. It’s all about the hats. There’s a video of CombatGirl in a TF2 Engineer’s suit, if you’re interested. Joystiq has the story.
Character customization is a game, a very powerful game. Trading gear and items turns that game into a multiplayer experience, which is even better. More video games out there should have this sort of flexibility.