Mario Kart 8 came out a year and a half ago. Slow down, man. XD
I guess I'd like to see a Battle Mode that doesn't suck balls like 8's, even something in line with 7 would make me happy. I would also want at least 40 tracks instead of the usual 32. But what I would want the most is a Smash 4 system of online play, where you can do it for fun or to increase your VR.