We knew it was coming, but now we have some additional info thanks to Game informers new cover feature. The new Arkham game will be called Arkham Origins and will be a prequel with a large bit of influence from Frank Miller's Year One take on the character. It will feature many of the initial meetings between Bruce and his assorted rogues gallery, including his first match up against Deathstroke (featured on the cover).
The game is being developed by WB Montreal, who has all the previous assets from the Rocksteady helmed titles, so hopefully the transition will be smooth. Other titles have had the same transition to release to mixed results (Ultimate Alliance 2 for starters). There is also a handheld title in the works by Armature studios, which will serve as a sequel of sorts to Origins.
While I'm a bit nervous about the handoff, I am excited to (hopefully) get more time in Gotham proper instead of just the walls of Arkham. I'm hoping that the detective work portion of the game gets expanded upon. If there is going to be DLC I would love to see more mystery style packs where you have to solve a set of crimes and ultimately fight the villain responsible--it would be a great way to get some of the b and c list villains in the game without taking away from the main plot. The game releases on October 25th for all current gen consoles as well as the Wii U.