It looks like Nintendo has changed the design of the Wii U's controller, adding control sticks instead of discs. The above photo was reportedly tweeted by a QA tester at TT Games, but has since been removed. As you can see, the control discs featured in the original controller design are gone, in favor of more traditional sticks. Check out the difference:
We don't know if the above photo represents the final design of the Wii U's controller. But I sincerely hope so. I've gotten my hands on a Wi U at CES, and while the disc controllers worked fine, I did wonder why Nintendo didn't go with the more traditional joystick.
We should learn more about the Wii U (hopefully a LOT more!) at E3 2012, an event G4 will be all over, bringing you live coverage, interviews, videos, demos and many surprises, so don't miss it!