Not really, try playing Mario Kart Wii with surround sound. It's a whole new experience. I can only imagine Mario Kart 8 being even greater but....
At least if you boot into Wii mode, it does have Dolby Prologic II. That's the crazy thing about this. The hardware is there to do it and Wii mode does it. However Wii-U does not.
WTH?