Some Tegra X2 derived Chip would do. I don't think Nintendo would accept a standard X2 chip anymore now with the CPU being vulnerable to Spectre and Meltdown, so NVidia could tailor out a slightly updated version of that chip without it's vulnerabilities and maybe some performance bump along the way. That would then also allow to block the current exploit which allows for the homebrew channel and anything that goes along with that.

Xavier which is the successor of the tegra X is 8K capable. Currently only used in machine learning and cars atm so was the switch processor.

So really..,we have already seen the switch successor but in other things. 

Switch SOC was also in Google Pixel tablet.

Well worth the wait.

It is capable of outputting 8k.
It does not have the capabilities of rendering modern games at said resolution, Do not conflate the two.
The fact it still uses LPDDR4 just reinforces that fact, the chip simply lacks the bandwidth to handle high resolutions. - Expect 1080P and less for that chip for most games.

The launch Xbox One for instance is technically capable of outputting at 4k, but that box struggles to even maintain 1080P.

As for Xavier... That is two generations of Tegra SoC's ahead of the Switch. (Switch uses Tegra X1, Tegra X2 is Pascal, Xavier is Volta based.)

Can't argue with you there. Zelda had been getting a tad stale over the years. Skyward Sword even dropped most of the exploration aspects from the series. BotW brought it back to it's core roots, and then some. 

Xavier also has a very big silicon footprint and a hard leaning into CPU improvements. It is not viable for nor intended for mobile consumer electronics and definitely not a Switch kind of device. X2 is the obvious Switch Pro chip. It brings improved memory bandwidth (iirc), higher power and heat efficiency that allows for much better clocks, CPU improvements, etc. Pair an X2 with an increase to 6GB of RAM (with the OS taking up just under 1 GB, that leaves 5 GBs for games), and you have a very nice upgrade for a Switch Pro to help extend the platform's life. But if Nintendo wants to continue with Nvidia beyond the X2 for the Switch successor, it will have to likely be with bespoke chip sets developed in collaboration between Nintendo and Nvidia.

Problem is that Xavier's design is really not suited for Videogames. The Volta's Tensor cores would be useless in games, hence why there ain't any PC graphics cards with Volta chips on the market, either. Add to this a TDP of 30W, and you can see why Xavier won't make it into a future Switch console.

While it still uses LPDDR4, Xavier has a 256bit connection instead of the usual 64bit (dual channel), meaning it has a 4 times higher bandwith than what you would normally expect with LPDDR4. It reaches 137Gbit/s, on par with low power GPUs (for instance, an Radeon RX 560 with 16CU only has 112Gbit/s). The GPU is rated at 1.3TFlops, roughly the same as the OG Xbox ONE (1.31, the S is clocked higher and thus a bit faster at 1.4TFlops)

X2 is still much more probable for the reasons cited above. However, with their weakness to Meltdown and Spectre, Nintendo could ask to create a new version without that weakness, and NVidia could very well take some cues from designs that came after X2 for this.

There's also the possibility for Orin, a newly announced Chip in the Tegra line. But since that one is supposed to be 5 times faster than Xavier it probably goes with yet another TDP increase, hence even less likely to be used in a future Switch.

I'd agree with you if we're talking about flat games, but on the other hand the PS4 Pro is a real treat fo us VR lovers over here! Skyim VR just got a patch some days ago and ever since then it looks marvelous on the Pro while being way way more blurry on the standard PS4. 

As for the topic, I really don't care. I think the Switch is good enough as it is.

I do think Nintendo may be better off bringing out a new Switch to compete with PS5/XB4, but I am a huge supporter of revised consoles throughout the gen. The PS4 Pro and XOX have both kept their respective ecosystems viable for someone that has upgraded to 4K and 7.1 surround. As OdinHades mentioned in the case of PS4 Pro, it offers a very clear upgrade when it comes to VR.

 I would like to see them take things even further, offering more tiers, and more revisions during next gen. I know people will say get a PC if you want power, but I have no interest in PC, and would like the option to drop some serious cash into a great Console(s), that have tech that goes toe to toe with the best Single CPU/GPU PC on the market. The XOX is even better in this regaurd than PS4 Pro, and that is why I was very quick to support MS after they released this beautiful console.

Couldn't agree more about the improvements in VR. The differences are very noticable. I gave my brother my original headset, and I play with it on his standard PS4, and it is really nice coming home to my Pro. I also notice quite a difference with my 75" 4K HDR display between Base and Pro. It is much more noticable as time is goes on. God of war and Detroit and more noticable than previous games, and I am wiling to bet Spider-Man, TLOUPII, and Ghost of Tsushima will push things even further.

Custom Tegra Xavier would be the ticket IMO.

Full sized Xavier is way too big and beastly ... it's 5 TFLOPS at an amazing 30 watts or so, but they probably could deliver Nintendo a custom build that could run at 600 GFLOPS undocked/1.7 TFLOP docked (1/3 of a full size Xavier).

That would be an insane portable, basically any current gen title would be portable, and even probably a good number of PS5/XB Scarlet titles if you're OK with 540p-720p portable.