DC announced that the movie will come out in 2014.

Source: Bleeding Cool

DC revealed that they would be making an animated adaptation of Batman and Son sometime next year. In addition, an "Assault on Arkham" movie was announced based off the popular Batman: Arkham series of games. It was hinted heavily that Kevin Conroy would be voicing Batman in one of the movies. The movie joins Justice League: War on DC's animated movie slate for 2014.