According to one of The Daily SuperHero's contacts, Batman vs. Superman is currently scouting and considering filming some scenes in Washington D.C. and overseas in Morocco. The source implies a desert scene (or sequence) is being considered in the film, hence Morocco. However, the source clearly stated that this should be considered rumor as of right now since it's via word of mouth. Back in August, there were other rumors saying the film may shoot in Toronto and Morocco, so the fact Morocco has been brought up again could mean there is serious consideration of the overseas location.
For the moment, take this with a grain of salt until official locations have been confirmed and announced. It sounds like Warner Bros. and DC Entertainment are still in the process of scouting locations before production begins in early 2014.