They should bring back most of the previous characters like Diddy Kong, Bowser Jr. and Birdo while also adding characters like E. Gadd, Kamek, and Baby DK. And every (or most) of the characters should have unique attributes and a special.
I'd also like it if every item that has appeared in the Mario Kart series returned in MK9, as well as adding new items based on Mario's power-ups like the double cherry, cloud flower, rock mushroom or ice flower. Seeing as how all these items can make a race extremely hectic, a balanced preset should be used as the default and there could be an option where you can select the items that you want for a race or cup and save these as your own presets.
As for the rest idk... a story mode would be nice but I feel it's not that important.
