All these images of Catwoman were also in Game Informer this month along with a walkthrough of that section. Essentially, Two-Face is trying to execute her to up his reputation among the other gang leaders in Arkham City, Batman goes in to rescue her, she slashes Two-Face and manages to escape with Bats. They talk, and she leaves. There's no mention of any co-op play during that section, so for the moment I'd suggest cooling our jets on who the potential co-op partners are. It /could/ be her, but what they're showing is just part of the early story, so who knows who will show up as the game goes on.