Mario "128" is ... a ways ... off.

[A Black Falcon]

GameSpy: What is going on with Mario 128?

Miyamoto: It's moving along secretly like a submarine under the water. When developing, we often look at the different hardware and run different experiments on it and try out different ideas. There have been a number of different experiment ideas that we have been running on the GameCube. There are some that we have run on DS, and there are other ideas, too.

At this point I just don't know if we will see that game on one system or another. It is still hard for me to make that decision. I am the only director on that game right now. I have the programmers making different experiments, and when I see the results, we will make the final decision.

http://cube.gamespy.com/articles/518/518839p1.html

From this nice interview... read the rest. :)