Let's see what Nintendo says because they know 100 percent and rumors have just been shown not to even be 10 percent.
If the gpu like sega said it high then I'm pretty sure the rumors about it being 4850 is false because it's good butnot surpisable.
With so many rumors about upgrades and stuff nothing is for sure but later on it will.
"We're very sensitive, of course, to trying to do all of this at an appropriate price. So I don't know that we would be able to sit here and say that it's going to necessarily dramatically outperform the systems that are out now."
"The system itself hasn't really changed. In order to maintain a consistent development environment, you really have to fix your specs at one point and let people know what they're designing for, so they can make good progress,"
And the Wii U likely doesn't have a GPU as powerful as a HD 4850 that is over 4 times as powerful as the X360's Xenos which would certainly be dramatically outperforming IMO.