Initially coming from the book
"Harry Potter - The Magic of Cinema" (which contains a preview for Part 2), this picture must be a screencap from towards the end of the movie because the two stars are wearing their final battle clothes, as seen in the trailer.
Occlumencia also seem to think more promotional material might be on its way:
"Fingers crossed that Warner Bros marketing department will be providing some more official pictures next week."
Harry Potter and the Deathly Hallows - Part 2 hits theaters July 15th!