We brought you a shorn answer to this from Nintendo’s roundtable at E3. Here is the long story.

“So it’s true that Mario was able to fly with the Tanooki suit in past games, but there was also, I believe, a form that had a tail and ears but couldn’t fly? And one of the reasons that we decided to go with the “Raccoon” Mario style in this game is that flying does present some interesting issues in three dimensions. You do have the slow fall, which makes certain types of gameplay more accessible, but having the character fly in 3D on the smaller 3DS screen would have been a little bit difficult. So we decided to bend the rules of the Mario world [on the 3DS] and solve that problem.”

“So actually the idea for the Tanooki suit came originally from wanting to put a tail on Mario, and so we started off by putting a tail on Mario in Super Mario Brothers 3 and we wanted to use that tail so he could do the little spin move and hit enemies with his tail, as sort of an attack. But then, once we had the tail on Mario, we thought: We’ve got this great tail. Isn’t there something else that we can do with it? So, then the next thing we started to do was to have the tail kind of flutter back and forth, and we thought that that’s kind of like a propeller, so that flutter motion would make Mario a little bit lighter, so he could jump further. But once we started doing that, it felt so good that we said; ‘let’s just make him fly’.”