The guys over at GameInformer got the chance to play as Catwoman in a story mission and challenge rooms at the E3 a few months back. Here's a few tidbits from the article:
"Rocksteady says that Catwoman is about twice as fast as Batman but approximately half as strong. I’ll save you the math, and just say that she plays very differently from Batman".
"Because Catwoman is so nimble, her takedowns are a bit more spectacular to watch than Batman’s. While he’s happy to knock a few skulls together and call it good, Catwoman’s equivalent attacks incorporate handsprings and stiletto-heeled kicks".
"As I worked my way through the Joker’s minions, I earned Riddler medals for meeting certain criteria. For instance, one of the assignments was to take out an enemy silently from above. No problem. The medals can be cashed in to buy special combat modifiers (regenerating health, aggressive enemies, disabled gadgets), which can be used to spice up the combat challenges further".
This seems to confirm that Catwoman is not just a re-skinned Batman. Hit the link below for more on what Catwoman can do, and what GameInformer thinks of the use of 3D in the game. Batman: Arkham City drops on October 18th, 2011.