Consider this planted firmly in rumor territory: the only lead so far is an image saved from Gamestop UK's homepage, that lead has since vanished faster than Batman himself... jumping... over a rooftop... and swinging out of site.... Exactly how does he vanish like that?
Best Buy previously let slip that preordering Batman: Arkham City would secure gamers the ability to play as Robin in certain challenge maps. Gamestop seems to be following up that bonus with their own retailer-exclusive skin for gamers to salivate over.
While the Batman Beyond skin has only been spotted for a moment, and only on Gamestop UK's site, I think it's safe to say you've now got some choices in where to preorder the Dark Knight's next outing.... and by choices, I mean Robin is still clearly the way to go. This Batman Beyond skin looks terrible!