The main appeal of the Wii U, other than the promise of Mario and Zelda in HD, is its large controller with a fancy touch screen. That controller wasn't ordained to be a controller from the start, though.
"During the roundtable discussions there were such arguments about should we make it capable of being a standalone system or should we make it work only with the [base console] system," Nintendo president Satoru Iwata told Gamasutra. Like one of those homemade GameCube portable units, then, only official. Thankfully, Nintendo quickly came to their senses.
"We came to the conclusion that this controller is only going to show the images generated and processed by this hardware unit—and sent from the hardware unit wirelessly. That means sharper graphics. A battery couldn't do that."
Iwata also revealed that planning for the Wii U began all the way back in 2007, which is when Nintendo first decided that using a second screen would be the way to go for its next home console. He also said another early idea for the console's controller was to have the second screen separate from the pad as a standalone device.