h2ohno on 20 October 2016
It'll do great in japan, less so in the rest of the world.
As a hybrid it can tap into the handheld market which has always been bigger for Nintendo than the home console market. Plus with the combined approach development won't be split between 2 systems, meaning more games for the switch, and more games means more sales.
So depending on the price, battery life, and marketing it could be anywhere from 30-60 million in total sales. If everything plays out right I could see it rivaling the 3DS in sales.
