It was mentioned in Miyamoto's interview on why there was no F-Zero title, and he was surprised that people want a new title because he thought there wasn't anything new to add to the franchise.
Forgot about Medievil, but I'm not sure if the formula it uses would survive in this current generation. I think if a Medievil game is to be created, it will recieve a major rehaul. (They were going by a Medievil move game but canned it.)
Also Crash has been mentioned in this thread, but I personally disagree despite Crash 2 being one of my absolute favorite platformers. I was gonna mention Jak and Daxter, but the reboot Naughty Dog was gonna go for sounded absolutely horrible so I'm glad they realized that fans didn't want that. The series is fine as it is.
Also, I know the last title for the series has been released this gen, but since I doubt it'll ever be revisited I think Metroid Prime should return. Viewtiful Joe should see a nice return as well.