Latest Iwata Asks show reveals some of the inner components of the Wii U and the revelation that the toughest thing Nintendo had to solve was keeping the prototypes from overheating. They said it took a while to optimize the air ventilation design and power consumption but they've fixed the problem with recent model designs.
http://www.egmnow.com/articles/news/...gn-challenges/
According to Nintendo, New Super Mario Bros. U will be the first game from them to be in 1080p resolution when its released as part of the Wii U's launch. Demos of the game were rumored to be in 720p but the actual game will be in 1080p.
http://www.destructoid.com/nintendo-...p-236490.phtml
Warner Bros released a video showing off all the gameplay and tablet upgrades the Wii U version will have compared to last year's PS3 and Xbox 360 versions.