Talk about uncomfortable. Nintendo admitted that it's presentation of third-party games for the Wii U showed scenes from PlayStation 3 and Xbox 360 versions, not those built for its own console. Says TechSpot:
The Wii was never known as a graphics powerhouse so the company was eager to offer a glimpse at the graphical capabilities of its next console in a handful of upcoming games. As it turns out, however, the videos shown on stage were coming from PlayStation 3 and Xbox 360 versions of the games. Nintendo of America's Reggie Fils-Aime confirmed this in an interview with GameTrailers shortly after the show, where he explained that the Wii U is still a year away from launch but games coming to the platform will look at least as good as they do on the PlayStation and Xbox.
So, Fils-Aime was just trying to illustrate the console's promise.
"In terms of how good it looks it's going to be driven by what the individual developers do. It's going to be 1080p, it's going to be high definition," promised Fils-Aime. "You're going to see games that take full advantage of a system that has the latest technology and can push out some incredible graphics."
Here's some video:

[youtube http://www.youtube.com/watch?v=QltIRk-Q6h8&w=560&h=349]

Source: TechSpot