Yesterday, Nintendo revealed all sorts of new Wonderful one zero one specifics, like the promise of a demo. That demo is obtainable now.
The demo was obtainable yesterday in Europe and Japan, but we weren't confident exactly when it was coming stateside. Booting up the Wii U eShop confirms that it is in truth available now. I am downloading it myself as I type.
Thanks to Clint Alvarez for the news idea!