Screens are one thing, motion is another. Then you have to account for objects on the screen and things going on in the background. Personally, I think the PS4 (and most likely the next Xbox) are in good position from a technological point of view. It is early so we won't see the 'leap' yet. I recall people were doubting the power of the Xbox 360 when it first launched because the games didn't look much better than PS2/GC/Xbox games at the time, and then we had Gear of War a year later and all doubts evaporated. Let's see how the Wii U games compare to the PS4/Next Xbox around say ... November 2014. :)
Either way that doesn't matter really. The Wii U is an HD console and that's good enough for me. Mario or Link on a system that is > than PS3/360 = Win.