You guys are lucky.
Not sure if my rear projection has issues or not, but standard def satellite programming looks horrible on this TV. It looks a lot better on the 32" CRT I have upstairs.
If your Wii looks great the way it is, save the $30 and put it towards another game. The standard sports pack looks fine, nothing to brag about, but games like Call of Duty and Zelda are two games that come immediately to mind that I end of squinting while I play because of the blur over the entire image. I played Zelda today for a few hours with no eye strain. The resolution looks the same, but it's cleaned up a lot.
I setup my camera and tripod to take these two shots. You decide which has the better detail and sharper image:
480i Composite
480p Component