I'm gonna say 13 mil minimum with the possibility of 14 mil. Next year Vita goes away, 3ds falls further and PS4 is out of things to pull sales from, so NS will have the Japanese theatre all to itself. Combine that with Pokémon and animal crossing and I think it may very well do 5mil or even 6mil+
Ya that's not happening, that would be 6.2-7.2 million
When the herd loses its way, the shepard must kill the bull that leads them astray.