Warner Bros. has registered a domain name for ScribbleNaUtsRemix.com, suggesting that developer 5th Cell might have a new Scribblenauts game is in the works.
Given the word 'remix' in the title, it's safe to assume this won't be an entirely new game, but a mash up of content from the first two titles. It's possible that this could even be a 3DS title.
Super Scribblenauts was released last year, and while it was praised as an 'innovative step' for the series, it still suffered from 'lacklustre puzzles'. You can read more in our Super Scribblenauts review.