I have a feeling it was an April fools joke on the author of that article.
Valve, the guys who brought you Half-Life, Left 4 Dead and Portal said that “Wii U seems to be a lot more powerful than the previous generations”.
Crytek, the studio who made Crysis – often touted as the most graphically and technically powerful first person shooter game ever made – said “Wii U development kits are very powerful, the specs are very good.”
THQ, the publisher bringing Darksiders II to Wii U said that it’s “just a lot more powerful than current HD consoles. It does 1080p very easy.”. Darksiders II developers Vigil Games seem to agree – they were one of the first developers using Wii U development kits – they even said that the Wii U version of the game will likely be the best version of the game “just because the hardware is more powerful and it will have some extra features that I think will actually be useful to people playing the game. With it’s controller, it might be the best version of the game.”
EA Games, Ubisoft… the list goes on. But even further, there are various anonymous sources saying the Wii U is twice as powerful, or in some cases 4x more powerful than PlayStation 3 and Xbox 360.
http://aussie-gamer.com/rumor-2/debunking-the-under-powered-nintendo-wii-u-rumour-is-surprisingly-easy/