The tech demo looks like it was done by the Tokyo team, it has that "perfect", almost plastic look that the characters in SM3DW have. Zelda U won't look like that, but I would expect a look that is at least moderately "dark" like TP, because that sells, and you can bet that Iwata is telling them to make what sells. I also wouldn't be surprised if it looks a bit like ALBW. But if we really want to guess at the all-new look of Zelda U, I would suggest browsing the art world. In the past they used old Disney style animation and watercolor... I could see a new art style being used for inspiration. Claymation or puppets? Ancient Greek paintings/sculptures? Origami? Renaissance? I think there will be a hint of something from the art world.
