Aaron Eckhart has been cast as Harvey Dent/Two Face in the next Batman movie: The Dark Knight. I haven't been following casting for the next Batman movie that closely, but from what I understand Eckhart was a fan favorite for the role. He joins Heath Ledger playing The Joker, and I asssume Aaron's role will be smaller than Heath's.
Also on the "strong rumor" list is that Maggie Gyllenhaal will be replacing Katie Holmes in the upcoming Bat-flick.
I guess you have to have a love interest, even in a superhero movie, but I would have perferred it if they had introduced Harvey Dent in Batman Begins as a friend of Bruce Wayne and/or Commisioner Gordon. That way it would have been that much more powerful when he changes from good-guy Dent to bad-guy Two-Face. We would have gotten to know him better and it would be that much more painful and tragic when things turn for the worse.
But... who am I to complain? I thought Batman Begins was excellent and I have high hopes for the sequel since the same team is behind it.
I found out about this from Joblo.com, although it's also being reported elsewhere.