Whomever said Nintendo Switch is right.

I don't think they should

The Wii U was plagued from droughts, so a unified library is the reason why the Switch lineup is really good. If they release another 3DS successor, then they will have to split their teams again and would put them back to a similar spot like last time.

May as well release a Switch 'Lite' version that can't connect to the TV and is cheaper

4D3S Switch.

Multiple revisions of the Switch are replacing the 3DS.

Already, quite a few people choose the current Nintendo Switch over their own 3DS to take on the go.

Here are some ideas:

With the hardware departments combining I imagine the new "dedicated" handheld will just be a smaller Switch of sorts.

Unless they stick to thier Nintendo magic, in which case the new handheld will be for an non-mutually exclusive medium like VR that the Switch currently does not support.

Le Switch it is.

I honestly think there will be portable and hybrid models to the mid-gen redesign.

"With the Switch off to a great start and likely stealing sales from the 3DS family of systems, it's time to start asking ourselves what we'd like to see from a dedicated handheld from Nintendo in the future." 

A switch, is the successor to the 3DS.

"Certainly it's a possibility that there won't be one, given the handheld nature of the Switch, but for hypothetical purposes how would you design the next system?"

I wouldnt, they just need to get the Switch down in price. Done deal.

Make a Switch Mini (differnt screen (cheaper) & without HD rumble) thats abit smaller and lighter, cheaper. Where the components arnt ones apple needs.

"And would you buy it?  And if so...at what price point."

A Switch? sure... price point? 199$-249$ bundled with a game. I think it launched too expensive, because of that gimmicky HD rumble BS. Sadly Im not sure if its likely to see a price drop anytime soon, because of that HD rumble & shortages on components and bidding wars with phone makers.  This is the "Wii U gamepad" type of situation, where its more expensive than it needs to be, nintendo would have had better sales if it didnt include some of those things but made it lighter/cheaper.

Switch hardware at 14nm, no joycons, clamshell design, 4.2 inches screen instead of 6.2.
In summary a Switch with more portability and longer battery life.

Where's Nintendo Switch Plus? 

I want a Switch about as compact as 3DS XL. If they can do that then we only need Switch.

But handheld gaming devices that run Windows 10 are also desired.