Angelina Jolie actually said that she'd like to play the role. As did Sarah Michelle Gelar and Kate Beckinsale. Personally I'm hoping it's Kate.
What's with the obsession that half of American males with Angelina Jolie? I just don't feel she's attractive at all. In Wanted, she looked like a square-jawed man. Kate Beckinsdale and Sarah Michelle Gellar aren't heartthrobs either.
Personally, I'd like to see Ra's Al Gul return with his daughter Talia. Delve deeper into the Society of Assassins. If they had to replace the Joker, I'd suggest James Franco (from the movie Pineapple Express), as he is very similiar in appearance to Health.