Heh, Miyamoto has never really cared for F-Zero. I wouldn't expect to see another F-Zero until he steps down from Nintendo, unfortunately. I also don't understand this "have to have a new idea" thing. They churned out three Animal Crossing games that were essentially the same before mixing things up with New Leaf. Heck, Super Mario 3D Land for Wii U is proof that Nintendo doesn't really require genius new ideas to develop a sequel.
Miyamoto on Finding New Ideas
"Hmmm new ideas...new ideas...need new ideas...got it! A cat tail! A freaking cat tail! We'll put it on Mario! It's brilliant! Welp that's all the energy I have for new ideas today, sorry F-Zero."