NX Q4 2016 seems unlikely NOT to happen.
Wii U will have been 4 years on the market by then, which while relatively short, isn't unheard of nor unacceptable (especially for a console with sales as low as Wii U's). 3DS will be close to 6 years old by then. The time will be ripe.
Nintendo Network ID: Cheebee 3DS Code: 2320 - 6113 - 9046