RobFox64tm
Member
To clarify how Wii U works; it upscales EVERYTHING to 1080p, if that's what you set the system to output as. MOST games will be 720p native though, and as far as I know, this is the case for Mario Kart 8. Also, your TV will always show the signal as 1080p, so this could be causing a lot of misinformation. The only games I know for sure that have been confirmed (by reliable sources) as being 1080p native are Rayman Legends and The Wind Waker HD.