This doesn't mean that there's no point to leveling up a toon -- Staroscik reminded us that players will gain new skills and weapon techniques as they play, and the ability to equip different gear. These perks will make an experienced player a tad more deadly, but a newcomer that takes quickly to the shooter gameplay should be able to hold their own. It sounds quite similar to Call of Duty 4's multiplayer advancement.
Staroscik also mentioned the "alias" outfits that we've heard about in the past. The system sounds like it could provide a nice change from being a heavily-armed bad-ass, provided that there's some variety to the missions that come up.