...You know, there's always TIM BURTON'S Alice in Wonderland. With this being the Realm of Sleep and all of these clones appearing, it has a chance you know since Wonderland is basically a DREAM world Alice imagined herself in. Not to mention that it's TECHNICALLY an entire new world since it's actually an entirely different film only with the same source. It would definitely be the type of curveball Nomura would throw like the last few worlds. Not to mention that having two Wonderlands in the same realm would be totally weird and it belongs in the Realm of Sleep more than anywhere else. Besides, wouldn't this make a GREAT boss?
Also, we'd have new villains like this and the Red Queen and we could actually meet the Mad Hatter this time, instead of him being sealed in a painting for some weird reason...
They're also already doing a Tron: Legacy world in DDD.