Prediction: If NX does very well, Splatoon 2 will sell 10 million+.

[Soundwave]

If NX is unified, then Splatoon 2 should be available to way more than just 30 million owners.

Anything less than 55 million NXs I think would have to be a pretty huge disappointment seeing as how even the 3DS + Wii U will be in the 85 million range combined.