Something that pretty much copies the idea behind a PS VITA and VITA TV. Console games on the go and connecting your handheld to a tv isn't very stealable to begin with. The Switch Tablet is more powerful and a bit bigger. The only thing that is stealable are the detachable controllers I guess.

Get real.  Nobody who was not already a Nintendo fan was suddenly converted here because of detacheable controllers.

Detacheable controllers on their own are not particularly attractive, that is why Morpheus didn't get any response.
The difference is that Nintendo has fans that are ready to gush over whatever they put out.  So what's new?

A good # of Nintendo/Switch fans here are clear they dislike the detachable controllers, but don't care since they aren't forced to use them.

I have no problem saying it's vaguely neat design, that could be useful for some people/niches...  So what though?  
That doesn't logically lead to Nintendo having stumbled over a gold mine that Sony and MS *MUST* lust after "copying" Nintendo.

Why is it copying Nintendo when you fantasize Sony/MS needing to compensate, but not copying Morpheus when Nintendo uses the idea?

And Sony already has their own single-hand detached alternate controller:

BTW, did you notice the thread on PSVR content already in 1 month outselling VR competition which has been out for year?
Does Nintendo need to copy that?  How are they going to do that?

Well SEGA Nomad came out many years before Vita and TurboExpress came out years before both. SEGA Dreameye came out years before Eyetoy(DreamEye also had the idea for YouTube 7 years before it happened). Nintendo had a camera for Gameboy and had a motion camera for GBA at E3 2002 but never released but was on the show floor.

The thing that will make the swich unique and that will be hard to copy for other companies is that Nintendo will throw it's combined Library behind it.
It should have fantastic first party support throughout it's life, if this works out.

That is something neither Sony nor Microsoft will be able/willing to replicate. Sony has far too much riding on the success of the Ps4 now, to bring out a hybrid console that gets all of their AAA games and Microsoft frankly doesn't have that enticing of a first party in the first place. Both of them place way too much emphasis on specs to ever do something like the switch.
It just doesn't fit their businessmodel.

As for the opportunity to play games on the go, I can see their streaming services pick up the slack eventually.

The reason MS and Sony copied Wii's idea was because Wii was a big success. MS and Sony will copy Switch if Switch proves to be another major success.

Sony's next handheld will be built on the same x86/GCN/GDDR5 tech that powers the PS4. It will be the same as the PS4 to PS4 Pro. All PlayStation games going forward will play on on PlayStation devices. So basically, if you want to build a game for PlayStation, it will have to scale down to the PS4 Phone and PS4 Handheld, it will have to run on the PS4 Slim and Laptop/Tablet, and scale upto the PS4 Pro and future Pro+. 

Sony is building it's hardware future and network services future around the PlayStation division. They have a wonderful scalable hardware design that is scalable from mobile to high end home. They will stick to this tech for many more years before shifting gears to compeletly new architecture in the mid 2020's. 

Basically we have, Microsoft, Sony, Apple, and Samsung leading the tech industry. Microsoft is focused on the productivity crowed, Sony is focused on the gaming crowed, Apple is the style and social brand, and Samsung is the casual brand.

Why would they? No offense to Nintendo who I love but it isn't actually all that exciting or innovative and doesn't really gel with the direction Sony or MS are taking.

If anyone it is companies like Apple/Samsung etc. that Nintendo fears. It wouldn't be much of an effort for them to make controller modules attachable to their upcoming line of tablets.

It's not like Sony and MS were successful with their takes on motion controlling. The Wii was released in 2006. Kinect and PS Move way later and they couldn't take away any oomph off of Wii sales. Apple and Samsung on the other hand have a tight grip on a market and target audience Nintendo is aiming at. You should take a look at the reveal trailer again.

Nintendo copies themselves, that's not the discussion. They also already showed interest in VR.

Why should they copy it? It's nothing unique. And Sony already have the same with Playstation TV.