A new post was made in Batman Arkham’s official (and verified) Facebook page which indicates that Warner Bros. will be showcasing something new within the Franchise
As expected it isn’t clear what does Warner Bros. plan to reveal: A new and a massive DLC, or a new title. Arkham Origins didn’t really make an impact unlike the previous titles, so its a matter of time to see if this would be worth the effort.
You have to question the choice of timing, considering most will be partying at New Year’s Eve. Not much clue was given in Batman Arkham’s page, except that it will be a ‘special announcement’.