Before those two Batman movies debut next year, Justice League: War will be released, although a specific release date was not given. Justice League: War is based on the "New 52" comic Justice League Volume 1: Origin, written by Geoff Johns and Jim Lee.
It is believed that both Son of the Batman and Batman: Assault on Arkham will debut during the second half of 2014, but nothing has been confirmed, including cast members and filmmakers.
Son of the Batman is based on Grant Morrison and Andy Kubert's 2006 comic book series Batman and Son which centers on the son Bruce Wayne had with Talia Al Ghul 10 years prior named Damian Wayne, and Bruce's attempts to connect with his estranged son.
Batman: Assault on Arkham is said to be a movie tie-in to the popular video game Batman: Arkham Asylum, which is loosely based on Grant Morrison's 1990 graphic novel Arkham Asylum: A Serious House on Serious Earth.
We'll keep you posted as soon as voice cast members and filmmakers are announced for these upcoming movies.
Justice League: War was released February 4th, 2014 and stars Alan Tudyk, Michelle Monaghan, Shemar Moore, Sean Astin, Christopher Gorham, Justin Kirk, George Newbern, Jason O'Mara. The film is directed by Jay Oliva.