Soundwave on 14 January 2017
50-55 million life time or so is my guess based on what we know now assuming the impact of mobile doesn't continue to hurt portable sales.
My guess is that it'll have a solid launch but then have a lull as it struggles at $300 before rebounding out a better holiday season.
It will find its legs in 2018 once Nintendo redesigns it (14nm or 10nm die shrink for thinner/more power efficient model) and can cut the price down to $199.99.
