I don't know, but I see the power difference between the PS3 and XBox 360 as being mostly pointless and only worth arguing if you're a fanboy ...
I could be wrong but I think Nintendo choose a reasonable piece of hardware with the Wii. If you look at the Gamecube's real-world performance (15 Million polygons with textures and lighting or 0.81 to 1.62 polygons per pixel at 480p) the graphical hardware improvements of the Wii should should put it close to hitting the limit of what can be displayed on 480p; certainly, you could add more pixel and vertex shader effects but they tend not to be that noticeable at 480p and would drastically increase development (and potentially hardware) costs. Basically, the Wii is well suited to fit the needs of the majority of people who do not own HDTVs yet.
