Hans Zimmer has confirmed that he will be scoring The Dark Knight Rises. He recently spoke with PopcornBiz.com and had this to say:

“He was going to come over next week,” chuckled Zimmer. “We start early. I know he's puttering around with ideas, and we sort of sneak up on things.”

“Working with Chris, he gives me all the freedom in the world and encourages me to go and be daring and unusual and crazy and all those sorts of things and be able to be the sort of emotional center of the film,” he told PopcornBiz. “It's very give and take. I'll start long before he starts shooting. Our conversations start there and it goes both ways: we just have conversations about the movie and less about what the music has to do, and it really comes out of that, whereby I felt that there was a real emotional core to be had and that that was something that the music had to do and I hung on that for dear life.”

(Source - PopcornBiz)