Batman: Arkham Knight lets you play as Robin, Nightwing, Catwoman - trailer
Not long until now until the third part of the Arkham trilogy is released - here's a new trailer showing some interesting team-ups.
Update: According to publisher Warner, the game will feature a "dual-play" mechanic that allows players to switch between Batman and his allies - Catwoman, Robin, Nightwing - during combat. It's not quite co-op, but it sounds like an interesting alternative.
Original story: It looks like Robin, Nightwing and Azrael will all be making more than a cameo appearance.
Batman: Arkham Knight is due on June 23 on PC, Xbox One and PS4.