He will be completely rebooted but seeing as it will be by one of the same writers (David Goyer), I doubt very much that he'll be completely without any resemblance to the most recent incarnation. I'd expect them to be adhering very closely to the formula, with the obvious exception that this Batman will live in a world populated by superheroes.
I expect it'll just be a slight variation of the Nolan Batman. His Gotham will probably still look like modern day Chicago and have the same grounded, realistic feel, and he'll still wear black rubber armor and drive a similar kind of big, tank-style Batmobile.
In fact they might even try to suggest that this is a further evolution
of the Nolan Batman (albeit with Bruce still wearing the costume). At least in spirit.