I like the idea of choosing characters to represent. Not playing as Luigi/Yoshi/etc., but you have their colors and emblem on your kart.
Also, as awesome as the ride and AR integration sound, I am a bit wary of how that tech will work. I'm not looking forward to Gringotts/Kong-level tech issues at opening. And if it's in KidZone, it'd be ANOTHER attraction that requires glasses, 3D or not.