The information below comes from Eiji Aonuma. In addition to the quotes below, he said that the Skyward Sword team did not make the Zelda Wii U demo. However, Satoru Takizawa, art director of Legend of Zelda: Twilight Princess, was deeply involved.
“You probably remember that when we introduced the GameCube, we showed a somewhat realistic Zelda demo. And what we actually created was the cel-shaded Wind Waker. So when we show a graphic demo, people think, ‘Oh, this is what the next Zelda will look like,’ but that’s not necessarily the case. I’m on one of the committees that oversaw the general steering and direction. We talked to each other a lot about several elements, one of which was, ‘How exactly will the HD graphics work?’ In doing concepts for that … we used Zelda assets quite often to examine, OK, how real will we make this look?”
One of the features of the Zelda Wii U demo allowed the inventory/weapons to be displayed on the controller. These elements could also be moved to the television. But Aonuma says that he’d like to bring much more to the table when an actual Zelda game for Wii U is made:
“I’d like to do things that are more surprising than that.”