Re third party support: they appear to be doing some things right on a technical level. They recently joined the group responsible for OpenGL, and Vulkan which suggests that their next hardware will support industry standard graphics APIs. Since Nintendo is not usually the third parties' priority they need to lower the barrier to getting ports.
Also, although Japanese console gaming seems to be going through a period of decline, I think Nintendo has a good chance of getting support from Japanese publishers. It is rumored that Square-Enix is on board with NX in some capacity and, given the amazing success of Monster Hunter on Nintendo hardware, Capcom should be there as well.
i think you can look at recent partnerships for a glimpse into the future: capcom, square enix and sega should all be there in some capacity. bandai namco will be there in a fairly big way. atlus too.
really the only big-ish company that man not have much is falcom. nintendo's done well to get third-parties back on the japanese side of things.