if you want to know how powerful is going to be all you have to do is look at these 3 quotes from nintendo themshelves
Miyamoto: Talking about the Wii U, it is going to be compatible with high-definition TV sets, which are now widespread and, with the graphics capabilities catching up to the general trend, some people consider it to be the "next-generation Wii." On the other hand, as far as graphics capabilities are concerned, there are already other hardware systems with similar functions.
Genyo Takeda: If there is anything that I can answer today, perhaps on the question of how the developers will be able to reproduce attractive visuals in HD graphics by using shader functions, but the fact is, a number of the developers have already had sufficient experiences on doing so on several hardware platforms. In other words, they have already experienced and overcome the challenges in this regard. But if I stop here, my remark will be interpreted as, "So, the Wii U has just caught up with the trend" if I borrow the words that Mr. Miyamoto just used. So, how to differentiate the Wii U in terms of brand-new uniqueness with other video game systems is important, and regarding this point, all I can say today is, we now have the new controller which revolves around the original concept of the Wii Remote, and the developers can take advantage of multiple screens, which enable them to leverage upon the unique combination of a big TV screen and a smaller screen in players hands.
Iwata: Looking at the software for home console systems, there are certainly the software titles for which very rich graphics must be reproduced on HD displays and which demand a large number of developers to spend a very long time to develop. It is one of the truths that a certain number of such software titles must be prepared, or the consumers will not be satisfied. But we do not think that any and all the software must be created in that fashion. When you look at Nintendos software, extraordinary rich graphics, massive gameplay volume and astonishing rendition effects are not necessarily the appealing point. It is, in fact, important for us that our games are appealing in other ways as well. - As we will showcase the Wii U at E3 in June this year, the detailed announcements must wait until then, but we are aiming to make a system which shall not be forced into competing with the others where the contenders can fight only with massive developer resources and long development times as their weapons.
please deal with it