Rocksteady Studios revealed some new information on Batman: Arkham Knight at E3 2014. It seems that the developer was planning to include the Batmobile from 2011 itself and was always planned for release on eighth generation consoles. It was also deliberate to not have Scarecrow in Arkham City and in Arkham Knight, you’ll be dealing with plans that were created over a long period of time.
So yes, mind games are on the menu for the Dark Knight. As for playing as a Batman villain outside of a simple mini-game, Rocksteady revealed that switching from Batman to a villain would break the immersion of being Batman. So while you had the choice to play as other characters in the other Arkham games, it always cycled back to Batman in the end.
As for the new Batsuit, it’s created as a military-grade armour. As a means of taking on Arkham Knight and his army, Rocksteady created the Batsuit and Batmobile to appear to be designed in unison. That means elements from the Batmobile are integrated into the suit.
Batman: Arkham Knight is currently slated to release on PC, PS4 and Xbox One in 2015.