As a wholly new Batman will be onscreen in Batman vs. Superman, a brand new costume will need to be designed. Not only will this ensure there is no in-universe confusion with regards to Christopher Nolans trilogy, but it also easily distinguishes the Ben Affleck Batman merchandise from all the other iterations. CBM (admittedly not the most trustworthy of sites) claims to have exclusive intel on the new Batsuitspecifically the cowlwhich they say will be inspired by the 2011 graphic novel Batman: Noel.
While not wildly different from recent iterations, the Noel suit is grey instead of black and looks a bit weathered, which would be in keeping with the seasoned, tired, and weary Batman that Affleck will be playing opposite Henry Cavills fresh-faced Superman. But again, this rumor is wholly unconfirmed and CBM doesnt exactly have a strong track record with scoops, so take this with a grain of salt for now.
In other Batman vs. Superman news, Batman on Film (which has a more solid reputation) reports that the new Batmobile will be a significant deviation from Nolans Tumbler designs and will have a markedly less military look. This isnt a massive surprise, as Snyders DC Universe is entirely separate from The Dark Knight Trilogy so it will inherently look differentand it should. The team behind the new Batmobile is General Motors, the same folks who built the vehicles for Transformers 4, so Im guessing well be in for a more car-like look.