I feel like we aren't thinking out of the box enough. A base system that isn't portable, a portable only system, a clamshell - these aren't surprising form factors for Nintendo.
The Switch was surprising. The DS was certainly surprising. Hell, the 2DS was even a surprising form factor.
....unfortunately, I'm just not clever enough to think of something legit surprising.
I'm thinking it will be a redesign of some sort, but I'd like to see them stick with a more modular design for increased Switchability.
My wildest speculation in terms of form and function (without getting too much into the feasibility in terms of marketing and tech of making all this work) is:
Switch portable will be the new base model Switch; it will be a PS4 Slim/Xbox One S approach, meaning it will run better, be sleaker, and cost less. The tablet will be slimmer with similar screen dimensions and resolution, but better quality and less bezel. Passively cooled, looks a bit more like a tablet.
Joycons are detachable but redesigned to be more ergonomic yet technically smaller, even though they are more comfortable to hold. Still have the same features, but the tablet docks into the Joycons rather than the other way around. Allows it to be both more securely attached as well as not get placed on the wrong way like the old design and get stuck. New design allows the SL and SR buttons to still be technically reachable even in handheld mode. New design also allows for TATE mode docking in the Joycon, which allows you to play that way but it must be the normal orientation to charge them. Kickstand also works in portrait and landscape mode. Left joycon buttons are still separate but resemble a configuration closer to the Dualshock D-Pad, allowing you to more easily rock your thumb. New Joycons could now accomodate larger screen/larger Switch in the future if they want as well as a smaller screen/Switch since they are no longer tied to the height of the system.
No dock included but a redesigned dock will be sold separately that uses less material, costs less, and is basically the old dock in a new slimmer shell. Redesigned dock and kickstand no longer have issue of breaking because you forget to close it. Still dockable and has performance just like old Switch both portably and docked, but able to get better battery life and hit docked performance while passively cooled due to the new chips/die shrink (ok, I know that they may be a real world issue, but this has a design point for why it works this way).
Price $200 + $50 for the new optional dock, maybe a low margin initially, but will make more money in the new customers they bring in as well as when it gets cheaper to produce over time. Original Switch gets a price cut to $250 and slowly phased out over the next year or so.
Nintendo will release a Supplemental Computing Device. It's function is to give certain cloud computing benefits, starting off with simple things like faster downloads and patch updates and eventually the end goal will be more advanced cloud gaming computations and even helping with streaming (probably not doing cloud streaming on it's own). Having it connected online sharing your computing power gives players certain benefits like voice chat/party chat, larger cloud save storage space, video streaming. At it's most basic level, it will have benefits using it with both an OG Switch and the Portable Switch, even without docking/connecting it. Has 8GB of RAM.
The twist is that it is actually the same chipset as the Portable Switch, so it is actually a Console Switch as well and plays games on your TV with "docked" performance. Joycon are not included, since it's sold as an SCD, but it would retail for $130-$150, and you can either buy Joycon separately or buy a Pro Controller bundle. Would make a "console" Switch a comparable price point as the "handheld" Switch when all is said and done for people who want just one form but don't want to pay for additional features. May have the highest margins per unit sold.
Now this is where it gets really wild:
The "Switch Pro" is actually a bundle of the SCD and the new Switch Portable for $350 and this is where we see some functionality added to the SCD that can only be taken advantage of with a Switch docking to it, and even functionality that can only be taken advantage of by having the SCD and Portable, specifically due to the new chips. The SCD adds active cooling for potentially taking more advantages of the power benefits with higher clocks and will be able to push passed performance of the OG Switch on it's own but it would be a performance mode that wouldn't really be programmed for on it's own when running as a "console only" for "docked" performance. It would though be able to get some performance boost with the portable hardware actually adding computing power to the SCD rather than the other way around, with the OG Switch getting minor benefits but the portable Switch getting almost Next-Gen Switch 2.0 upgrades if they want to take advantage of it (again, don't know how practical this would be). The SCD would also have an extra set of Wifi antennas because it would essentially be able to function like a Wii U of sorts by streaming video and computing between the portable Switch and the SCD. This wouldn't allow for the "next-gen" performance boosts", but at the very least, I could see it work at a "hub" for multiple Switches connected like a LAN, it could have some Wii U functionality, whether through a form of backwards compatibility or just making new games using the same design philosophy, and going back to streaming, it could help cut down on latency by having a "middle man" handling a lot of computing/decoding, but maybe that all is just bullshit because I don't really understand cloud computing.
So the basical TL;DR breakdown:
-Switch "Portable" basically a redesigned, sleeker and cheaper Switch, no dock, but redesigned sleeker dock will be sold separately that could work with this and OG Switch
-SCD/Console Only Switch/Hub - plays Switch "docked" games on it's own but requires separate controller, lots of performance benefits when paired with a hybrid Switch, both OG and Portable and potential for cloud applications as that technology matures
-"Portable" + SCD bundle = Switch Pro; full benefits of the new chips when docked to offer potential for "next-gen" growth to be unlocked over time, as well as maturing cloud tech and a real next-gen "Switch 2" being able to really evolve the system over time. It is the "future proof" Switch SKU.
-OG Switch will eventually be phased out and replaced by the "portable" but would currently be able to take advantage of some SCD benefits. Allows current owners an option for getting "Pro" level games as it would be a higher performance target, but not as high as the potential of a "Pro" bundle, which would overlap into the next-gen for Switch.
Sounds convoluted, but I think it could be pretty easy to explain:
OG Switch and "Portable" Switch will be comparable but one has a dock while the other doesn't. At the same time, the portable is like a new iPhone in that is seems smaller, but the tech actually makes it more powerful, even if it doesn't necessarily use the full energy efficiency as a portable except for longer battery life. There will be new redesigned Joycon and a dumb dock, the former is for the new Switch while the latter could work for both if you like.
There will also be a "Smart Dock/Hub" which technically can run Switch games as well, but it's purpose is to add some online/cloud functionality now and more in the future. It can also beef up your OG and Portable Switch to a higher performance level when docked, and allow some level of streaming benefits when undocked, but if you buy both the new Portable Switch and Smart Dock together, you can get an even higher potential performance in the future as well as features that only the new architecture of the new hardware can enable, features that will likely be in a Switch 2, which you can get a taste of now or upgrade at the pace you want with the modular pieces that you desire.
TL;DR of TL;DR : SWITCH PRO IS LITERALLY 2 NINTENDO SWITCHES DUCT TAPED TOGETHER! ;P
Yeah, so that's my wild pipe dream, but I think there is a kernel there of ideas that I just think could be so compelling if it's possible, but it seems pretty unrealistic.