Mario Kart: U Behind the Wheel

[Tattletale1]

They could have 5 races each, and 5 cups in both Retro GP & Universal Grand Prix for a total of 50 racetracks!
The disk would hold that much...
Plus the addition of customising Mii outfits with parts bought from coins earned from winning Grand Prix, and Mission Mode.
(more noticeable on Rocketskates and Battle mode don't y'think?)
Connecting to 3DS to share Characters and courses would be great!
...and a new Mario Kart Channel can allow Mario Kart Wii to play more Tracks, connect to 3DS, use 3DS style Wii-U Miis, and use the Wii U controller.

[tacopill]

I would like to see multiple vehicles, similar to (but not exactly the same as) Donkey Kong Racing; in addition to having Rocketskates from the Sonic stuff.

Also, having a First Person Perspective from the Wii U controler or 3DS would be cool.

[Tattletale1]

It'd be cool if it had up to eight players, it would make a nice battle mode, but Double Dash Karts should make a return..,
'''unlocked once you get all the characters!  Or at least 16 for multiplayer mode...
In Co-Op, your screen can look backwards if you're in back, for a team with two Wii Remotes, a Rear veiw miror is displayed; in Wi-Fi Co-Op, you could chat with your teammates using the mic!  And your photo (or live snapshot) taken in the style of Mario Kart GP Arcade will be shown as you pass opponents!
Double Dash will have its own seperate mode, but use the same tracks...

Battle Stages should make room for only six people, making all eight player battles very chaotic.

[KidIcarus]

What if they had planes?