While I cannot confirm it's real or fake yet, using the old poster as evidence of it being fake is flawed. For one, the background is totally different, placement different etc. Second, they have adapted the posters before, as seen in those images.
Exactly. Im trying to explain that too on Polish Pokemon Forums. --- Official Arceus of the Pokemon X and Y boards ~The God of Pokemon!~
Hope it's on the grounds of it looks like the worst alternate forme yet. So they basically took Mewtwo's tail...and shifted it to his head -_- --- Official hot fudge sundae of the IDF Official Hydreigon of the Pokemon B/W 2 Boards.