That has more to do with advances in the game engines and optimizations. The increase in the way that games look now compared to then is directly related to optimizing for the consoles, as their power level is constant. The same will happen with Wii U. Once devs get familiar with the hardware (and the toolsets become available to allocate resources more efficiently), you will see and increase in output. It won't be as drastic as this gen, of course I highly doubt the PS4/Xbox3 will either.
That was my point. WiiU launch games are not representative of what the hardware will be able to output when it's being put to use by devs that have experience with the new hardware, their engine, that are developing on the system as either lead platform or exclusively etc.
Log4girlz likes to ridicule this by stating all the devs must be rookies then.