That is pretty sweet. But we don't even know if Nolan is going to do a third Batman film much less include The Riddler as the villian. I'd rather have two great films and no third one then two great films and a medeocar third Batman.
I love this poster. I believe it was an officially generated tease. To prepare the new mass legion of fans for what is to come. I also believe that the riddler is going to be in the film. It would make for a great film. B/c he is as iconic as the Joker. Also, it would make for great viral sites, such as what Nolan did for the Joker in TDK.