So given the Dark Knight's insane run at the box office (the 'will it beat Titanic?' murmurs have begun) it's inevitable there will be a third. The big question is who the big bad will be. It seems from the film they intended for Heath Ledger to reprise the Joker in some capacity next time around, but as we all know, that will (probably) not be the case.
Geoff Boucher writes an open letter in the LA Times today to Chris Nolan offering some advice. Some of it is good. By process of elimination, he id's Catwoman as the only logical choice. I agree with this. Harley Quinn might make some sense if they attempt to follow the Joker thread (recasting just doesn't seem proper), but of all the Batman's rogues, she is the most sensible in Nolan's realistic concept of the character. However, Boucher's choice of actress (I'll let you click the link to see) doesn't do anything for me. Not that she's a bad actress, but what Catwoman needs, like the Joker, is someone who approaches it with a take no one ever considered. Give it a read, it's interesting, and so are the comments.