Don't get your point. Skyward Sword has a huge Skyworld you can explore. The smaller areas are on earth. The newest Zelda on the 3DS has a huge world to explore.
Super Mario 64 and Super Mario 3D World are not the same kind of game. I am sure there will be another Mario 3D game thats more like Galaxy or SM64.
The next big "exploring" game from Nintendo will be "X" and that will be huge :)