The next Xbox and PlayStation are not "GPU-centric." There are pretty significant things happening with their processor architectures. And at least for Durango, it's not using off the shelf kit, contrary to what many GAF posters have insisted. Even more troublesome for the Wii U, they have much more dedicated GPGPU capabilities which aren't happening on the dedicated GPUs they're packing.
This is why, in addition to other reasons exposed in this topic by other more insightful posters, I still feel Nintendo are doing the right thing from a business perspective.
From a consumer's perspective, it definitely sucks. We all wish for the cutting edge technology when it comes to new pieces of hardware, and it sure would have been great to have a more powerful machine in addition to new functionalities that still have to prove themselves. That being said, I canot say I am surprised as this is most definitely in line with Nintendo's policies during the last few years or so.
Most of the comments in this topic, I feel, are pretty harsh and perhaps justly so - that we shall know in the months and years to come - but honestly, when I think about it, I am perfectly happy with having Microsoft + Sony and my PC catering to my "powerful hardware" needs while the last market actor explores different avenues. So yeah, there's definitely more of a market for a device like the Wii U than just soccer moms. Whether it will be financially viable though will probably boil down to the quality of the software at the end of the day.