In a recent Iwata Asks interview Shigeru Miyamoto assured fans of Super Mario Galaxy that the release of Super Mario 3D World doesn't mark the end of that sub-series.
Although World is the "present culmination of 3D Super Mario," that doesn't mean Nintendo's team is team with Super Mario Galaxy games.
Commenting on the matter Miyamoto said:
"The same team can't make both [Super Mario 3D World and Super Mario Galaxy] at the same time. And we can't bring in a second party and slap the name Super Mario Galaxy on it. I suppose we could idealistically make both in Tokyo, but we want to do something new too, so there was that dilemma."
Some interesting information on 3D World was also revealed in the interview. Players unlock Rosalina – the fifth playable character – by beating the game and her unique move is a "special spin attack".
The power up which allows you to control multiple characters as once was the result of a mistake – a developer accidentally used a placement tool to put two Marios into the game.
Regarding future Mario titles Miyamoto commented:
"Personally, I would like to take on a variety of new challenges with Super Mario Galaxy and design 2D Super Mario games in an easy-to-understand way within certain restraints."
Super Mario 3D World launches on Friday, November 22nd for Wii U. You can check out a recent trailer here.