Let's face it, a PG-13 rating for a Batman film, animated or not, is a given. However, one thing that can grab attention most, is the "sexual content" certification. This most likely suggests that Harley Quinn, Poison Ivy, or Catwoman could play a substantial role.
Batman: Assault on Arkham is an upcoming direct-to-video animated superhero film that is part of the DC Universe Animated Original Movies. The film will take place in the same universe as the Batman: Arkham video game franchise. Jay Olivia will direct. The film is set to release mid-2014.