After the great success of The Dark Knight, Nolan has decided to make a second sequel to the Batman Begins saga. Both Johnny Depp and Phillip Seymour Hoffman are the possible villans for the third installment.
That was taken from Christopher Nolan's Wikipedia page in the section titled "King of Gotham". I'm a fan of both Depp and Hoffman, so I'm interested to see where these rumors will go. Granted, it's Wikipedia and cannot always be trusted, but I think the combination of Depp, Hoffman, Bale and Nolan would make for a pretty fantastic movie.