According to Nintendo’s President Tatsumi Kimishima the NX isn’t being seen as a direct replacement for the Wii U or 3DS.
Speaking to the Asashi Shimbun newspaper and translated by Shun and GSR on NeoGaf, Kimishima explained “the NX is neither the successor to the Wii U nor to the 3DS. It’s a new way of playing games, which I think will have a larger impact that the Wii U, but I don’t feel it’s a pure replacement for the Wii U” after being asked how Wii U sales would be affected by the release Nintendo’s next console.
Little is known about the new console, still without a proper name and only known by its code name, NX.  All he would say on the subject is “It’s something very new. The hardware, the software lineup, all of it is something I’d like to play for the first time myself.”
Surveys and developer rumours have circulated hinting at a closer relationship between handheld and console, possibly with the handheld acting as a controller and with both being able to play the same games from the same media. Â There are even rumours that the console will look towards going back to cartridge or solid state media over discs.
The NX is due to launch in March next year, a delay from the expected Winter 2016 launch but one that seems necessary if Nintendo don’t want to replicate the bare-bones launch line-up that stopped the Wii U being an instant success.  Kimishima explains the issue “When people finish the launch titles, they will want things to buy in spring, on summer break, at Christmas. As such, it’s not simply a question of when the hardware’s ready; rather, we need to ensure our software lineup is also in a good place.”
Whatever the NX turns out to be, there are no plans for showing the console off at E3 this year, though rumours suggest there will be an unveiling at the Tokyo Games Show in September.