Wii games on WiiU look like HD remakes.

[SvennoJ]

The only difference I see is underscan vs overscan.

On the Wii with component cables my TV overscans the image while upscaling, makes it screen filling while missing a little of the edges. The Wii U upscales the Wii games for you and underscans them, ie displays them with small black borders all around, probably to use simple pixel doubling to avoid scaling artifacts 960p, exactly double each 480p line.

Just different scaling methods, exact same source material. A slightly smaller 1:2 mapped picture looks better than 480p upscaled to 1080p.