Director Christopher Nolan more or less said that Batman 3 aka the Dark Knight Rises would be the last installment in the rebooted Batman series. But the third opus, which hasn't been released yet, is likely to be a hell of a blockbuster, and for sure Warner Bros will want to continue the franchise. So I think it's not so far-fetched to think about Batman 4, a movie sequel to the Dark Knight Rises.
When asked about a potential Batman 4 movie Christian Bale kind of confirmed that he wouldn't mind to do one more film:
I guess that if Christopher Nolan was reluctant to come back and if some other really talented director was taking over the franchise Christian Bale would also reprise his role as Bruce Wayne aka Batman, but that's speculation for now.
Who could be the villain in Batman 4? Ra's al Ghul in disguise was the main antagonist of the first film and Scarecrow showed up. In the second film, it was about the Joker and Two Face. The third film's villain is Bane, and Catwoman is likely to play a part. So any idea who's the next villain Batman will have to face in the movie Batman 4? Any suggestion maybe?