There were some titters in the press a few weeks ago about David Tennant wanting to play the Riddler in the next Batman movie. Not that it really matters, since Nolan effectively quashed the rumour when he said he was avoiding the members of the Rogues Gallery that had appeared on the big screen before (excepting Joker and Two-Face).
But then someone had to go and make an awesome poster just to show us what it'd be like. God, I would totally see that film! And I'm a little bit disappointed it probably won't happen.
Can't exactly I'm sold on Kristen Bell as Harley Quinn, although after seeing her in Heroes I suppose she could do that kind of unhinged pretty well.