Pipes, riding yoshi, bowser as a bad guy, mario AND luigi as the heroes, unlocking playable characters as you go along, have 3d remakes of older levels, give us geographical locations of where stuff in the mk is, coins with no purpose at all but score and free men, unique enemies that haven't been seen as well as old ones, the ability to travel to different continents like dk island, or sarasaland,(like wind waker), peach and toad speaking english aloud, luigi speaking sometimes, and mario speaking never, bowser should growl with subtitles, mario items that you can find according to the place you are in (barrels in dk island, raccoon tails in the mk) the return of mallow and geno, a more in-depth look at star road and star haven, an explanation as to what happened to pauline, and as many frickin cameos as they can cram into it.
sorry if that comes out hard to read but that's the stuff they need to put in.
The world would be a much cleaner place if people would eat their own trash.