Guys we reached a point when graphics almost can't get any better.
The Wii needed an update because when it was launched , there were still the majority of people with CRT TVs.
Shortly after that, the LCD HD TV prices came significantly down and almost everybody today has HD TV sets.
Now the problem that I have with my Wii, although for me graphics don't really matter ( heck I still play monocromatic spectrum games from 25 years ago ! ) is that the Wii doesn't take full advantage of my TV resolution, thus outputting a less then optimal picture quality, compared to what my TV can do. Also another problem with the Wii, is that is not powerful enough to handle CPU intensive games like BAtman AA or AC II, hence lack of third party development for the platform.
With the Wii U , those issues will be gone. Native 1080p output and resolution provided, and more horse power.
I think I'll be all set for the next 8 years or so, or until a new kind of TV will come out that will make my WiiU look terrible.
Do I really need to discuss at this point how many polygons can be processed or how really is the hardware's power ?
The WiiU will be able to play the games I wanna play, now if MS or Sony develop an even more powerful system, it still won't be able to look much better on my TV, does it ?
And rest assured, whatever the next iteration of Xbox or PS will be, they'll take a lot of inspiration from the WiiU features.
History proves me right.