Don't let the title mislead you as Batman: Arkham Knight is less a reference to The Dark Knight and more a reference to the villain of the game.
Reps for Rocksteady told Game Informer that the villain of the game is actually the Arkham Knight.
"Yes. I can tell you his name is the Arkham Knight. And that's pretty much about it. He's a new supervillain that we've definitely had a lot of fun working on. We fell for this particular art. We wanted a new character in there. It works so well for this story that we're telling. We still definitely got all the classic characters back, and these are characters you all know and love. And then we wanted to bring someone new in who could push and test Batman in new ways. It was also great for us personally to have that opportunity to contribute a little bit to the Batman universe as well. He is going to be a formidable foe, I'll say that as well."
Batman: Arkham Knight introduces Rocksteady's uniquely designed version of the Batmobile, which is drivable for the first time in the franchise. The addition of this legendary vehicle, combined with the acclaimed gameplay of the Batman Arkham series, offers gamers the ultimate and complete Batman experience as they tear through the streets and soar across the skyline of the entirety of Gotham City.