Teresa Palmer was at one point cast to play Talia al-Ghul in a Justice League movie that was scrapped partly because of the Writers' Guild strike a few years back. Now, she wants to play Talia in The Dark Knight Rises, and to add to the conflicting rumors floating around for the past few weeks, the way she phrases things makes it sound like she has reason to believe Talia will be a character in the film. Or at least Bleeding Cool thinks so.
After The Scarecrow, Ra's Al Ghul, The Joker, and Two-Face, who should be Batman's next enemy in the Batman Begins/The Dark Knight series? Well, as of now we know that Tom Hardy will play Bane and Anne Hathaway will play Catwoman.
Check out the master list for all the villains covered. I've pretty much run out by now. Obviously, there are more Batman villains, but not any of significance that I know of. As of February 2009, no one is confirmed as a villain. Not the Johnny Depp Riddler, not Phillip Seymour Hoffman Penguin, nobody.