Just dropping in briefly (I've been avoiding the thread for spoilers) to say something:
"Fundamentally, I think a Mario game is the type of game that's really not about completing the game, but rather about having fun just playing. So, I made sure there were lots of areas in the game that could be enjoyed, even by little children, just by moving Mario around. In these places, you don't have to think about what you have to accomplish, so you can play around freely. I hope people who will play this game will find a special place of their own in the game, and discover their own way of enjoying the game."
This is from the interview on Wii.com that Iwata did with the SMG developers. One of the developers said this and it just struck me as the perfect expression of what I love about 3D Mario (and a bunch of other Nintendo franchises, for that matter). That's what I love about the games, just that sense that you can explore the world and move through it, unrestricted by goals. A playground, a new world, a different perspective. I think that's part of the reason I loved Mario Sunshine so much, where others didn't so much; they were goal oriented players, and I didn't care about goals (kinda odd, since I'm also a completionist; fun comes first though). It was just a fantastic and engaging environment to be a part of.
So, needless to say, this gets me that much more psyched about finally getting to play Super Mario Galaxy.