I totally understand you, they may be doing simple math with everything and trying to reach an average, something like...

It has a 40% better CPU

it has 3 times the RAM

It has a 50% faster GPU clock speed

bla, bla, bla.

And then they calculate the average and the number is something like 2.3 times more powerful than a Xbox360. It is not a reliable number, but even if this somewhat true I think it can reach my standards, good-stable framerate and 1080p output.

There are lots of things that people could be doing ...

One of the reasons we could be seeing different rumours about the capabilities of the Wii U is because people are heavily focused on one component. I wouldn't be surprised if the Wii U's CPU was only 50% or 100% more powerful than the XBox 360 processor in most real-world benchmarks because we're at an odd point in game development where CPU processing power is more than adequate for a scripted game world but falls far short of being adequate for a completely dynamic world; which means that there is not much need or value in really pushing the CPU at this point in time. In contrast, the GPU in the Wii U may be substantially more powerful.

I loved Ninja Gaiden (the one that was released for the Xbox in 2004), liked Ninja Gaiden 2 (just 'liked', not 'loved'), but the more I see of NG3, the more I get the feeling I won´t like it at all.

@bold. Very unlikely.

And the issue with the Wii was not that it was less powerful than the X3sony (PS360), but rather that the Wii was SD, and was not even on the same level as the other market players. Understandably this was to create a radical shift between them and their competition, but it was ultimately counter-productive. Nintendo could have had the all-around console of gen 7.

As for WiiU, even if it is not as powerful as the nextbox3 (which I doubt), it would still be on the same playing field, as PS2 was to GC.

Also, 2x as powerful is probably a horribly simplistic metric of comparative HW capabilities, like HappySquirrel said.

You know in Swedish we spell and pronounce “six” as “sex” so it would be "Nintendo Sex Entertainment System" for us here

Ninja Gaiden 3 looks incredible, glad to see these games finally on Nintendo's platform. I'm not a fan of the excessive violence though, but many elements of the game are high value and I'm glad Nintendo is finally getting these. Go Nintendo!

The Wii being SD is because it didn't have powerful next-gen hardware in it, the Wii U will be in the same position if this rumour is true. 

Keep in mind I'm speaking from the hypothetical scenario in which the Wii U isn't in the same league hardware-wise as playbox 4 (which is what the "2x as powerful rumour would suggest), I'm not saying anything about how likely this scenario is, not even saying I think it will happen.

abysmal loading times in NG3

Either way, at best in favor of your view Andre we'd have a PS2 to GC/Xbox scenario, where PS2 was the leader by a landslide, and in this occurrence WiiU would be the analog of PS2. Middle case, in disfavor of your scenario (and the more likely case), we will have a Sat/PSX vs N64 scenario, where WiiU and PS4 would be on par (due to budget limitations), the WiiU being the likely leader, and Xbox overkilling with bleeding edge. Worst case (the most different from what you present), is a scenario where all 3 have relatively the same power, no bleeding edge. In that case, chances are of the WiiU being the dominant platform.

But my predictions are a distraction to my main point that either way, no scenario is in disfavor of Nintendo's platform as it was for Wii vs HD twins. That should never happen again in the home console front if Nintendo learnt their lessons (which I believe they have given interviews and all).

I would call it NEAT:

Nintendo Entertainment Advanced Technology

It would sound and look good too! "Hey! I bought Assassin's Creed III on NEAT."