I think they are fine. I also own a PS3, and formerly a 360, and no, they are not equal to them, but then again, your talking 480P, if component, VS true HD.
Frankly, with as much fun as the Wii is, and with games like Zelda and SMG, it really doesn't matter. They look great all on their own, and the gameplay speaks for itself. (Also Metroid Prime 3 - looks amazing if you ask me all things considered).