Hmm the R770 would narrow it down a bit but there are 3 versions of the R770 core CE, LE and XT

CE has 640 Shader cores (basically the component that creates the "effects" stuff like lighting particles etc,) 32 texture units (used to apply textures to models etc) and 8 ROPs (the component that draws the final frame and handles anti-aliasing)

LE has 640 Shader cores, 32 Texture units 16 ROPs

XT has 800 Shader cores, 40 Texture units and 16 ROPs


for comparison the 360s GPU has 48 Shaders, 16 Texture units and 8 ROPs

But I believe that the Shader cores used in the 360 GPU are more capable per core but the benefit of having a lot more simpler cores should allow many different effects per frame even if they are not much more complex, but don't quote me on that.

But even the lowest end spin of the core (which is probably the closest to the Wii Us GPU due to the size of the console) should allow much higher resolution textures, the extra ROPs will probably be used mostly for driving multiple screens, but should allow more AA and possible more games running 720p with good graphics and high frame rates or even 1080p games, but that would make me wonder why none of the E3 demos including the Zelda demo had no AA.

Finally I would say it's plausible but I am still sceptical.

Why not? Care to elaborate?

Also, the Radeon 4890 uses the RV790 chip, which is a supercharged RV770 in any case...

I mean, it's absolutely possible for Nintendo to put these chips on the Wii U, as they have never been expensive, even back in 2008 when they were new.

And the RV770 (on 55nm) consumed between 110w and 190w of power, but that was determined only by the core speed (525 Mhz being the lowest and 850 Mhz the highest), being unrelated to the number of available shader processors.

Shouldn't have any problems with running current multiplatform games at 1920x1080 with 30 fps. Maybe even more once we factor in  optimisations for console hardware.

If this is Wii U gpu that's a healthy acceptable minimum even if Sony/ms come out with some kind of monster.

X360 shaders are equivalent to 160-200 unified shaders from RV770.

depending on clock rate of course which I imagine the Wii U would use a low clock rate to keep heat down in that small console they have. Especially since Nintendo usally use one or two ticks behind the current die size these days as they like to use mature processes with high yields from day one. 

O_o?

why not? , every new PC now uses Radeon HD 5xxx and the a little more pricey ones use Radeon HD 6xxx series's , GPU's aren't that expensive.

So, to summarize, WiiU is up to 4x more powerful than Xbox360 and is equivalent to PS3.