I think it will sell 7mil

Considering how it will likely be bundled on and off for years to come, how people love 2D Mario, and how the Wii U will likely be on the market through 2017, I think it can. 2 million a year for the rest of the Wii U's life would be more than enough, and can be done even if the Wii U sells as little as 25 or 30 million.

For all we know part of Nintendo's next strategy is a triple bundle. One retail game in the box and download codes for Nintendoland and Super Mario Bros U. So ongoing its in every wii u pack.

Depends on bundles.

If there's a Mario Kart 8 bundle at the same price, most people will choose MK8 over NSMBU.

Another question that could be interesting: how long will NSMBU be the best-selling 8th-gen game and which one will surpass it first (on a single console)? Mario Kart? Call of Duty? GTA?

Are they no longer bundling it or something???

This.

It all depends on how often it's bundled long term. I suspect that it will be replaced with 3D World over time, though, so I'll say no.

Mario games are extremely leggy, bundled and last for a long time so its extremely hard to predict but 5 million is a possibility. I'm more impressed of the tie ratio between Super Mario Bros Wii U and the Wii U sales rather than the actual sales of the game itself.

No. Wii U is selling too slowly. Launch titles and Nintendo games have great legs but not great enough to outlive the system's selling woes. I just don't see it happening.

Yes bundle

As a bundle I can see it doing 10 million easily over its life time (assuming 5-6 years barring any drastic management/policy change at Nintendo HQ).