It seems that we are now about a year away from the successor to the Switch. People are high on the Switch 2's prospects because the Switch is doing so well. It feels like people are expecting Nintendo to do something new by... not doing anything new. The DS, Wii, Wii U, 3DS, and Switch all had some kind of gimmick to them, but since the Switch has been working so well, it a lot of people are thinking Nintendo will just stay the course and deliver a similar console with a more powerful chipset and some QOL improvements.

Personally, I think Nintendo has to add something special to the Switch 2 to separate it from the Switch. I think it will be hard to convince people to upgrade based on improved graphics alone. Everyone likes shinier graphics, but people who are playing on the Switch are clearly ok with somewhat dated tech, and few of the Switch's best titles are graphical powerhouses. I don't feel like Animal Crossing fans are going to be all that blown away by graphical fidelity. A more modern chipset can help with third party support, but Nintendo's success has always been driven by first party. 

Don't get me wrong, I think the Switch 2 will do just fine if it is simply an visually upgraded Switch, especially if Switch 2 software is Switch 2 only. But, I don't think it would do quite as well as Switch, and not better. I think Nintendo will need some novel selling point to grab some headlines. 

If there is some novel feature, what will it be? 

The only thing I can think of is VR. I think VR is a technology that interests a lot of people. It hasn't instantly fizzled out like the 3D bandwagon that Nintendo jumped on with the 3DS. But, VR is having trouble in the gaming world because it is a niche market similar to Kinect of PSMove. Something like PS VR 2 is an add-on, and will only have a fraction of the audience that the PS5 itself will. Because of the low install base, developers will be reluctant to make software that really takes advantage of VR. Without that software, people aren't going to spend a few hundred bucks for the headset.

The Switch however solves a lot of the problems with VR. As we saw with Labo, the Switch can do VR with a dollar or so worth of carboard. With an improved chipset the Switch 2 should be at least as capable as the original PSVR. The Switch already has detachable motion enabled controllers. If it has the same form as the Switch, the Switch 2 would have all you need for VR, you would just need to include a mount, which would probably add about 10 dollars to the production cost.

VR capabilities kind of go well with the Switch. The selling point of the system was that you can Switch between different modes of play, handheld, tabletop, and tv. So, now there would be a fourth. VR hasn't lit the world on fire yet, but I think if it's coming along with something people already like, people would be more willing to give it a shot. Since every Switch 2 owner would have VR capabilities, Nintendo could develop some games that really take advantage of VR, even if not every title uses it. It could offer something new without really changing what people liked about the Switch.

That's my prediction. What do you think?

I really hope not

Just keep the original Switch concept with something above PS4 Pro specs

And good joycons this time

Hopefully nothing.
The Super Famicom/SNES may have decreased sales from the Famicom/Super Famicom but a lot of that was because of the strengths of the Sega Mega Drive/Genesis.
I know we're in a much different era now but pushing a bunch of new ideas or gimmicks for Switch 2 is a huge risk. VR is just about the only thing that makes sense, and it should be separate from the console. Sony was smart to never include VR with each PS4 and PS5, and Nintendo should follow suit. Release Switch 2 as is and have VR a separate purchase.

No. Their sauce is their form-factor, IPs and price point... and that's not a secret. As long as they don't step on their own feet like they've done in the past after doing well, they should be fine. 

Interesting thought experiment/prediction. My initial reaction was that VR seems a bit too tech intensive and niche, but you make a good point about it not needing to have high specs at all - Nintendo has often had great success with generation old specs, so why not do the same with VR? And if anyone's going to get the mainstream to go crazy for VR it'd be Nintendo.

I wonder if Nintendo in a way was testing the waters with VR/MR - in the form of Labo and Mario Kart - with a view to its next home console. But all of those games sold poorly - the first Labo only shipped 1.42 million last we know, the others didn't even hit 1 million, and Mario Kart: Home Circuit didn't fare much better at 1.58 million, despite having the Mario Kart name attached at a time when the franchise had never been more popular. Those results might lead one to the conclusion that it's too risky and more likely to lead to WiiU-style sales than anything else... or another conclusion could be that for VR to work it needs to be the almost sole focus of the console and especially its PR from day one.

I would rather they take away some features tbh...

Sure it's a risk, but I think you have to have something new to entice people, and I don't think better graphics will be enough when visuals were not a major selling point to begin with for the Switch. Plenty of people will have had enough fun with the Switch to upgrade, especially if the games are good, but I think something new would be needed to maintain or eclipse the current level of success.

VR is a technology that a lot of people I think would like to try, but just not at 300+ dollars. It wouldn't have made sense for Sony to include VR with PS4 and 5, because that would have meant at least a 600 dollar pricepoint. The Switch already has VR ready controllers and its own screen so you just have to add a few dollars worth of plastic. I think to the average consumer, the value added is going to far exceed the cost.

Did those games sell poorly though? 

If you compare Mario Kart Live to Mario Kart 8, sure. But, this was a game you play with an RC car and have to set up a track around your house for. Clearly that's something that's only going to appeal to a fraction of MK8 owners. What is a reasonable expectation for something like that? I have no idea. Intuitively I think 1.5 million is kind of good, but I don't know much about the RC car market. I don't see a lot of good comparable here. Similar for Labo. It's I'm pretty sure the only video game where you assemble a controller out of cardboard, so I just don't know how to make an estimate of what success is in that context. 

I don't think either of these products are a good predictor of how a VR Switch would do. And I don't think it would need to be the sole focus. Similar to how the Switch can do motion controls, and has a few fairly successful motion controlled games, but that's not the focus. I would say VR should be a bigger focus because I think it has more potential as a selling point, but I don't think it would need to be the main or sole focus. One or two major VR titles a year, VR mode in other games where it makes sense (i.e. Prime 4 but not Metroid Dread 2), and some smaller titles (like a VR Wario Ware), would probably me enough. 

Sony has being able to keep similar levels of sucess of 3 decades now just releasing the same console with better hardware 

People don't keep playing in the same hardware for years after it stop getting software support. At least not customers who play more than two or three games per console. Even those who only buy Nintendo for Pokémon and Animal Crossing will keep buying as long their next installments keep getting released on Switch 2

Sure they might not sell as much as 150 million again, but is this necessary? I'm sure they can move easily 100 million units again just with a new more powerful Switch without taking any major risks. 

Having a weird gimmick in other hand can be detrimental if the gimmick in question is not good. Wii U and 3DS come to mind. 

This is a no-brainer. Release a more powerful console, call it Switch 2, make it backward compatible, unify your digital store and show trailers of new 3D Mario, Mario Kart, Pokémon, Metroid, Animal Crossing and Smash as games coming for the next 3 years and booom, another 100 million plus seller confirmed 

Having a weird gimmick can also be a benefit if the gimmick is good. Wii, DS, and Switch come to mind. The only Nintendo console that succeeded while being simply a more powerful version of its predecessor was arguably the GBA. Of course, Nintendo hasn't really tried that strategy in a while, so maybe it would work this time.

Sony's strategy is different. They have an audience that cares more about visuals. Nintendo's visuals have been a generation or more behind for nearly two decades at this point. So, I don't see that as a compelling selling point. There are some Switch owners who are going to buy the next system regardless, but there are some who got caught up in the hype, and Nintendo has to keep them excited.

I don't think a more powerful Swtich would guarantee 100 million. There are few guarantees in life. Even if it could, that is not a good strategy imo. I think you always need to be trying to grow and innovate. That sometimes leads to failures, and you can point to the Wii U and the 3DS, but if Nintendo had simply kept making more powerful hardware, I don't think there's any way they'd still be around as a hardware manufacturer. There is the cliche if you're not growing you're dying, and I think there's some truth to that.

I think Miyamoto already stated that VR isn't something that Nintendo wants to focus, because it isolates people instead of bringing them together (rough translation).

But it is guaranteed that the new console won't be just a simple Switch with upgraded power. There will be a new gimmick. Nintendo always wants to offer something new. Probably it's something which only a handful of games will use.