It's 2D Mario, of course it's going to sell pretty well, all the great marketing it's just a big plus for one of Nintendo's strongest sellers. 

Good thinking. I'm not super creative, so I suspect this game would get old fast for me if I have to rely on my own level-making. The more people that have the game, the more insane levels we'll get to see/play! 

Love it when Nintendo actually markets their stuff well. 

When Nintendo begins marketing this far from release, you know they're going all in.

And that's a good sign, because this game has potential.

Yep, it isn't like Nintendo is ditching the Wii U... oh wait. 

I'm not sure what this has to do with what I said.

In my defenition, if they were going all in they will keep supporting the Wii U. It isn't fair to those whoe invested into their console. Yes, it has good exclusives, but its hardly been out.

Super Mario Maker has tremendous potential to be Nintendo's next killer app. And it would seem that Nintendo themselves realize this and they're going all in!
Definitely a very good sign!
Although I kind of suspented they would give this game a strong marketing push anyways because of two things.
1. It's Mario
2. It's Mario's 30th anniversary.

When did they say they would stop supporting the Wii U, becuase I really don't remember that.

By "going all in" I was referring to the game, not the console.

Common Sense and going by history.