Super Princesses
I bet many of you, including myself, would love to see another game dedicated to the princesses (besides Super Princess Peach), and what better way to do it than giving the main roll to the 3 of them instead of just one
In addition, I would love if Nintendo got Daisy involved in more Mario games, not just the spin offs. I mean, there's 2 generic Toads in New Super Mario Bros. and no room for her? And she was absent in Super Mario 3D world too, and let's not talk about Smash... Oh boy.