It could be NX or it could be another win. These SoCs were designed to be an embedded solution for consumer electronics. It could be for a smart TV that can play games. Could be for any set top box such as the next Amazon Fire TV. You can sure hope that it is for the NX, but as many have pointed out, don't hope when it comes to Nintendo. They have been a let down since using carts in the N64.
For Nintendo fans and their target audience, the WiiU is close to good enough for a 1080p screen. If the OS was faster and it had more games, it would have been fine for those that bought it. Something that is slightly better than the WiiU is more than likely what they are targeting because the NX is all about re aligning their marketing strategy into something they hope will bring in new customers.
It's never been about competing with MS/Sony. If there is the opportunity to use the same chipset in both portable and in the console I think they would lean towards that. It would streamline their game development process and that fact alone could help them entice 3rd party developers.
One thing I need to ask myself here is do I need a console? I have a decent PC hooked up to my dumb TV that I will upgrade for VR and eventually 4K gaming. My consoles sit unused and I tend to pass, even on exclusives until I get bored and I can pick up a cheaper copy if they tended to live up to the hype. Does supplementing my PC gaming with a console make sense and if so which one do I want? I would lean towards Nintendo because it is different in the gaming experiences offered. But after the Wii and WiiU and even the GCN and N64, my Nintendo system has been a dust collector for most of it's life due to low game output compared to the PS, PS2, and now PC. I should sit this next round out and play Zelda on my WiiU, but will I?