Christopher Nolan is working on Batman 3

Giving little information as usual Christopher Nolan stated that he is writing on the Batman 3 script right now. His brother Jonathan has done a draft.
He mentioned this during a Q&A about Inception:

[youtube=http://www.youtube.com/watch?v=9kIc4TABeGE]

Batman 3 will arrive in American cinemas July 20th 2012