The Arkhamverse is expanding into animation. Batman: Assault on Arkham has Batman once again going against the Joker. However, for the first time in the Arkhamverse, he's facing off against the Suicide Squad, a team of villains who undertake black ops missions for the US government in exchange for shortened prison sentences. In the Arkhamverse, Harley Quinn, Deadshot, Killer Frost, Black Spider, King Shark, and Captain Boomerang are all members.
The upcoming film will detail Batman's encounter with the Suicide Squad, a group that was teased at the very end of Batman: Arkham Origins. Given the involvement of the Joker, it's clear that this game takes place closer to the Origins timeline than the upcoming Arkham Knight.
Kevin Conroy will reprise his role as Batman, while Troy Baker will play Joker. Here's the first trailer for the film, which is currently undated: