After getting my component cable today and hooking it up I was seeing artifacts like crazy in the wii menu. Like whenever you hit a a button you would see residual artifacts as it changed screens. It happens on all buttons and selecting settings or data.
If you go in your menu and disable noise reduction from that video source the artifacts magically disappear.
Also to set widescreen you have Wide mode button on your remote until you are at FULL setting. You can tell if you are wide or not by examining the right and left circle buttons on the wii menu. If they are oblong you aren't stretching your video and are set to widescreen.
Also disabled live color in the advanced menu afterwards, though this probably doesn't change anything.
Found out you can also force FULL setting in the menu. There is a default setting for 4x3 for each video source and you can tell it to default to FULL. So now when I turn my Wii on its at the correct setting everytime. No more pushing Wide button.
Sharpen is another big setting that if you crank it down it makes your Wii look better. Hell, most of the "image enhancement" crap that comes on TVs is terrible and really just gets in the way of clean signals (like Wii, DVD, 360, etc).