It features the Joker as the main bad guy and although he behaves a bit like the Jack Nicholson Joker in the original Batman movie with Michael Keaton, this Joker is not a joke (har har).
The movie is probably going to release around the middle of the year and it looks like the movie the original should have been. On the other hand the original Batman movie was right for the time. Chris Nolan’s movies are darker, less comic book movies and more action thrillers using comic book heroes. This Joker is far darker than the original Joker and that fits well with Christian Bale’s Batman.
(Source: Another Movie Blog)