Egann on 06 November 2014
It's basically impossible to tell. The new 3DS is basically an insurance policy so Nintendo can float or dump it as they see fit. A successor could happen in 2016 or Nintendo could hold out to 2020.
I imagine that Nintendo is planning to launch the Fusion by Christmas 2017. If the Wii U has a really great 2015 and 2016 that may get postponed a year to milk the market, but that's not likely.
So between 3 and 4 years, probably closer to 3.
