The question of whether it's a portable that can go home console, or a home console that can go portable, does sound like a weird semantic toss-up to me. I assume the real concern behind the thinking is whether we'll get significant console-style ports from other platforms beyond what Nintendo's gotten in the past. That's got to do more with the controller inputs and porting difficulty, I think.
(As an aside, would we assume that the NX would inherit all the third-party support that the 3DS has received? Because that'd be pretty awesome in my book and at least a START on rehabilitating third-party presence on Nintendo "consoles"!)
One exciting thing is that Nintendo's finally getting off the PowerPC architecture that they've been on since the GC. If true that they're getting on Nvidia's Tegra line, then it's sounding like they're really finally on something designed for modern graphics tech. The Tegra X1 is 4K capable, runs UE4, and is even ostensibly future-proofed enough for Vulkan. Sure the typical thinking for how to get to modern hardware would be to jump to an x86 AMD chipset, but ARM chips are all over the place too, especially in the mobile space that's seeing plenty of activity and competition to drive up performance and adoption and simultaneously drive down price.
One worry that I've been wrestling with in regards to the Tegra X1 talk though is that great as the Tegra chip sounds, it doesn't seem to make it to XBox One power. It's definitely above 360, and above Wii U, and that DOES put it in Nintendo's traditional target power target (Take last gen and multiply by anywhere from 1.2 to 2). However, if the great power console hope of 2+ Tera Flops is to be realized, then what we're talking about here with the eurogamer stuff has got to either be:
1. only the Mobile form of NX, with a Beefier Console NX still hidden from sight, or
2. just the initial dev hardware, with a Beefier Tegra X2 chip to be used in the real thing, or
3. that supplemental computing device talk is true and the dock for this will magically make it beefier, so players who want that experience can pay extra above the base mobile unit to get it
Possibilities 1 or 3 sound more fruitful to me.
Option 4 would be Nintendo's path of least resistance though: The Tegra X1 gets the GC->Wii treatment and is tweaked and overclocked and improved, but not at the same scale that other companies leap up. Taken on its own merits, it will be the most powerful Nintendo hardware created, be capable of amazing visuals, and have modern features, but it would definitely not be your 4K TV showstopper demonstration piece.