Nintendo NX is Coming March 2017
During Nintendo's recent 2016 fiscal year earnings report, the company announced that NX will launch globally in March 2017. Not more was said other than the NX will be a "brand-new concept".
This comes as a bit of a surprise, seeing as many rumors were suggesting a Fall 2016 release. Still, not much is know about the next project from Nintendo. The company only mentioned that they will begin to talk about it later in the year, after E3.
It is not uncommon for Nintendo to announce a new platform this way. Both 3DS and Wii U had similar announcements before any details were provided. Back then, both platforms used code names Controlle and Project Cafe, respectively.