It looks fantastic. It just proves that you can still make beautiful games, despite being on so called "underpowered" hardware. I guess Nintendo proved the critics wrong once again.
Furthermore, the gap between PS4/One and the Wii U isn't that large like many perceived, sure in terms of raw numbers and other measurement it might have it beat, but Mario Kart 8 shows that the Wii U can dance with the beefier boys - that much is clear now.