That would be hard to believe, because Nintendo doesn't have a history of releasing home consoles with those kind of specs, or at the prices that would make such a powerful machine profitable.
Correct, and that is my point. A rumor is only slightly believable if you believe there is some merit to it. It doesn't matter if this rumor has absolutely no factual evidence, proof, or support behind the claim. It only is believed since people's natural pessimism and that there is nothing to fear but fear itself.
Currently what we have in place for factual data to try and compare the Wii-U to is that the Wii-U can both run end-of-the-console-life PS3 and 360 games, as some of those are being ported over to the Wii-U. We have some demos, some of which looked quite nice especially for just quick demos. We also can relay the 3DS as being in-line with Nintendo's future plans.
How about a comparison? How many times stronger was the Wii to the Nintendo DS? Now how strong is the 3DS? How will that compare to how strong the Wii-U is? People already mention that the 3DS is, in many ways, more powerful than the Wii and that's a handheld.
We have a bunch of other rumors saying the opposite of what this rumor says, and several from far more credible sources than this one is coming from. The only reason this one is getting any light of day is because it is the only rumor making a claim that can be eaten up by the negative, biased, and stir controversy for page hits and such discussions like we're having now. I opt to not listen to any of these rumors since really, a measure of 'power level' means very little without the technicalities.
But at the end of the day it's the games that will be important and will make the Wii-U successful or not. The platform just needs to provide the power to support these games.