The Unlikely Duo, Batman and the Joker Team Up [UPDATED]

What you’ll see in the video below is a team-up I wouldn’t have predicted. In it the Joker and Batman partner up to fight a handful of criminals, but is this a leaked trailer or just another fan-made mod? If it’s the latter I doubt this is a taste of what’s to come in the campaign, instead I’m thinking this could possibly be our first glimpse at the game’s Challenge Rooms. But again, that’s merely speculation.

The only reason I can think of for these two guys to ever work together is if the Joker is a playable character in Arkham City’s Challenge Room mode. Wouldn’t that be exciting? Cooperative survival against waves of enemies and going by the video there are combo attacks to reward teamwork. What do you think this is?

Update: Embedding the video seems to have been disabled so if you haven’t seen it yet and would like to you can watch it here.

Source: Dead Pixels Video Game News for Rumor Mongerers