I read a ways back that this will be Rocksteady's last batman before they move on to new projects. But I wouldn't count out WB continuing batman games using Arkham Origins developers.
The franchise is a cash cow now, who could blame them. So do I think it will be the last? No. But I can't wait to see what Rocksteady comes up with down the road. Imagine if they got a chance to do Spiderman. A 100% quality spidey game...omg, it still has yet to be done. ;)