There's plenty of Eye Candy on the Wii as well. It's no slouch in that department. The difference between the NVIDIA chip in the PS3 and ATI chips in the Wii and 360 will not be evident in some games. At low SD resolutions (720x480) all the chips should manage full frame rate with a lot of 3D "wow"

Things you will notice on the more powerful chips in the PS3 and 360 will be higher resolutions (which require an HD set to use) and pixel-based filtering (anisotropic filtering is probably what one would notice right away). Per-pixel shading may also be easy to spot in some games, but it really depends how and where it's used for it to make a big difference. Model/object detail in some games is evident but in many it's easily lost on the majority of players. Obviously the faster chips can handle more tris/polys, but there's no guarantee a game publisher will even use different models for the various ports of their games.

At this time I can't say I'm overjoyed at the title availability for the Wii. Zelda is head and shoulders better than anything else on the platform right now. Easily 10-100x better than the other games. I'm hoping for more titles in that league sooner rather than later. Nintendo will need it to keep the console sales strong in the long run.