Orrrrr.... Just or.... they don't ever release detailed specs of their devices? Last I checked, they didn't do it with the Wii or Gamecube. Please correct me if I'm wrong here.
They are more protective now. They like to keep secrets for a variety of reasons. One is to not allow competitors to be privy to their R&D choices, therefore making it easier for competition to simply "one up." they also corporately feel that talking specs is counterproductive to talking games. I don't agree, but it has been that way ever since Iwata took over. He is a really cool guy though. Everyone likes him. and he knows his stuff. As a former developer himself, he appreciates horsepower as much as anyone. Nintendo basically HAD to do the Wii like it did. With the Wii U, they could do whatever they wanted. They chose a very powerful, very next gen, but not necessarily "nuclear" specification for the U. Probably pushing the envelope of what they feel is "wise." Rather than argue specs, Nintendo will argue games and let the actual products speak for themselves. Likely, the next systems from other companies will be hard pressed to distinguish themselves in the games arena.
In the GCN era, Nintendo worked with an unknown company called ArtX that was developing amazing graphics tech. The eventual GPU that resulted had less transistors than the Xbox GPU, but the GPUs both performed very similarly in the end result, sometimes the GCN graphics were even clearly superior. but all people could talk about was transistor count. People didn't understand specs. they only understood big number vs. little number. that's why Intel, IBM etc. don't market by ghx ratings anymore. People by and large didn't "get" why a Core CPU was "slower" than a P4. What they didn't realize was that the Core was doing so much more than the P4 per cycle that it blew it out of the water, but once you start having to explain things, you lose marketing momentum. That's what Nintendo knows and that's why they shy from it. ArtX ended up impressing everyone with their GCN work. So much so that ATI (now AMD) flat out bought them. and the 1TSRAM bit was genius. It allowed the GCN to compete with and sometimes beat the XBOX while costing FAR less and using less transistors to do so.
Take a V12 engine and it will be fast. Take a V8 engine, twin turbo charge it, and it will be faster while also being cheaper and getting better gas mileage.
The Wii U hardware is impressive. The P7 architecture, the EDRAM, the highly programmable GPU, the RAM in tandem with the amount of data on a Blu-Ray tech drive, etc... It is a machine built to simply handle business.
Sony and MS HAVE to have more cores with their X86 CPUs to keep up. They will also need more RAM to work with a less efficient architecture. If they don't, they will have to seriously custom fab their tech so much that the cost will skyrocket. And this is just to keep up. Both companies know they will have to outpower the Wii U to be relevent since Nintendo is signing developers left and right and then have their own world class games to compete with.
Their hype will be things like number of cores, ghz ratings, ram amount, things like that. Nintendo by the numbers will look like less than (just like the Gamecube did), but the actual games - not so much. That is why they don't play that game. they can simply point at their games and say "where is the difference?" or "are you really going to pay $200 more for such a small discrepancy?"
If you are a Nintendo fan, it is a good time to be one. Things don't always work out like this for a games console maker.