From the operating results PDF:
"For our dedicated video game platform business, Nintendo is currently developing a gaming platform codenamed “NX” with a brand-new concept. NX will be launched in March 2017 globally."
https://www.nintendo.co.jp/ir/pdf/2016/160427e.pdf
Also: Zelda is delayed to 2017 and:
"No NX at E3. Will focus on new Zelda"
https://twitter.com/mochi_wsj
Update 1 - According to Nikkei : "Features, price, software at launch and other details to be announced by the end of the year"
http://www.nikkei.com/article/DGXLASHD27H11_X20C16A4000000/?dg=1&nf=1
"For our dedicated video game platform business, Nintendo is currently developing a gaming platform codenamed “NX” with a brand-new concept. NX will be launched in March 2017 globally."
https://www.nintendo.co.jp/ir/pdf/2016/160427e.pdf
Also: Zelda is delayed to 2017 and:
"No NX at E3. Will focus on new Zelda"
https://twitter.com/mochi_wsj
Update 1 - According to Nikkei : "Features, price, software at launch and other details to be announced by the end of the year"
http://www.nikkei.com/article/DGXLASHD27H11_X20C16A4000000/?dg=1&nf=1