Topic. Seriously, how they'd do it? Is everyone else developing Wii games just super-lazy? Judging from this Gamasutra interview with High Voltage's Matt Corso, that is apparently the case. The Conduit's sharply detailed look isn't the result of a wonder-engine, but of meticulous hands-on optimization work.
[Matt Corso]: ... I would say that with systems like the Xbox 360 and PS3, you can use pixel shaders to deliver the great visual effects. With the Wii, things are a bit different, so we had to do a lot more under-the-hood optimizations to enable the system to do what it could do.
And then, even from the art content creation perspective, the system is a real balancing act, because you do have more limited texture space and whatnot, so you need to keep playing with your textures and your geometry resolutions and your lighting schemes to really bring out the visual style. It's not as easy as building your models in Zbrush, mapping to your low-res cage, and then just turning on the cool lights and you're ready to go.