oled display, rail reversed (you hold the switch and slide the joy cons down and out instead of up) and the charging port on top,

OLED has problems with screen burn.

They really DO need a top charging port though. It would also help in connecting wired acessories in tabletop as well.

I was wondering if the dock ate up the screen over time. 

As a precaution I immediately went to GameStop and got a glass screen protector for my Switch because I was paranoid about dust particles mangling my screen when pulling in and out of the dock.

Glad I did.

Reduce the size to make it a bit more portable.

I don't know how they could do this without making it a built in one unit or something though.

Better battery life in Portable mode.

Other than that, just moving some stuff around, such as where the kick stand is etc

EDIT: one thing I do think would be cool, and doesn't really need a new system for either, an option for onscreen controls. Ok, this would'nt be practical to play games like Zelda and stuff, but you could get more simplified games (similar to mobile phone games) then take the Switch without the joycons, making it much more portable though sacrificing the ability to play some games.

Better graphics card or gpu/cpu or whatever makes it more powerful. Also a slightly better battery.

Bigger screen and more battery power (Like 3 hours to 5 hours)

- Smaller bezels (Allows for a bigger screen on the same size factor).
- An extra USB-C for charging while in tabletop mode (Located right next to the cartridge slot).
- A backplate that doesn't scratch just from looking at it (Or maybe make it swappable like the New 3DS faceplates).
- Better kickstand with more angles to choose from.
- Better battery (+Add an option to play games with docked quality in handheld mode).

Hardware Revisions:

Switch Mini:
-Built-in controls
-About the same size as Vita
-Built in 2.4 GHZ RF connection to combine with a wireless headset accessory
-OLED (more than a luxury if anything)
-Shrink dock into a USB-C adapter (which is what the dock really is) and move the USB-C port on the system to the top.

Switch XL:
-Similar to the current Switch but with smaller bezels and a larger screen (essentially you get the same dimensions but with a bigger screen by reducing the screen to body ratio)
-Bigger battery
-1080P display with the ability to get TV mode's performance on the handheld when plugged into a power outlet
-Built in 2.4 GHZ RF connection to combine with a wireless headset accessory
-OLED (more than a luxury if anything)
-Shrink dock into a USB-C adapter (which is what the dock really is) and move the USB-C port on the system to the top.

- MS Surface-like kickstand that extends to the whole width of the system, with the ability to stand it vertically.

Switch TV (the 2DS of Switch introduced much later in the system's life)
-Inexpensive set top box -> about $150

Things I am not sure need a hardware update:
-Built-in voice chat: if Nintendo built the current Switch specs leave no resources for building in a universal voice chat feature, then they should make the revisions mentioned above slightly more powerful (probably by adding a co-processor or something) for built-in voice chat. If not then they should just release it as a software update. Having to voice chat through a smartphone is an atrocious solution.

How much would you think those two models you proposed would be? Hypothetically, they would be released in 2019 or something. I guess the only things that would be affected are the motion controls and the IR camera. Some games like ARMS, 1-2 Switch, Odyssey (to some extent), Skyrim (to some extent), Resident Evil Revelations 1 + 2, LA Noire, and Splatoon 2 utilize one of, if not both, these features in ways that affects gameplay experiences.

I'd like to see a smaller, more portable Switch. The only problem I see is that the Joy Cons can't really get smaller and remain comfortable for adults to use. So, I think they'll have to move to integrated controls on the base unit, if they're going to go smaller at any point.