There is so far no indication that there will be an additional GPU. Tegra X2 should be just fine in playing old games like Skyrim and every single Nointendo game for that matter. All we can hope for is an overclocked mode when docked.

Frankly an additional GPU would make the whole system very clunky from an architectural standpoint. The all in one approach is absolutely fine and will make things very comfortable for Nintendo and the developers. Adding another GPU in the dock would make the console more expensive and basically ruin the whole concept.

Then you're argument makes no sense. CPU to CPU, these Tegra's are better than the Jaguar. Jaguar is not a desktop i5 / i7 CPU. Jaguar is a mobile CPU based on x86 architecture. But, you're nitpicking one small part of the OP and not really worth the discussion.

I'm betting on something closer to 70-80% of an Xbox One overall. Something that when docked (aka home console mode), you likely won't see much of a difference between an Xbox One or NS port of the same game.

Do you think Nintendo will supply some special software to smooth out possible porting?

So taking out the one part of the OP I didn't agree with and questioning it is nitpicking now?

I understand. Next time I'm only going to post when all of the OP is questionable and not just one part.

Long live discussions!

1) No games are announced for it at this time.
2) Any games currently in development have many possibilities to not make NS launch well beyond tech. Companies have planned budgets and it is hard to shift that plan midway/late in the cycle.
3) From all accounts, it sounds like devs relatively recently have recieved dev kits (last couple months). This is why Nintendo is not confirming any games yet. These companies need time to use the dev kit and perform proof of concept with their in-development games on the hardware. By January that is to be completed and we'll see what 3rd parties will do. Specifically speaking of RDR2, I think Take Two enjoys money and if it will work on the hardware it may just come late when they can put planning/budget to it, unless the middleware being used makes the porting a very minor impact.

Nice breakdown. I personally feel it will be just a stone's throw away from Xbox One, perfectly capable of receiving ports (or even being the console games are made for to be ported up from there).

All they need to do now is implement an achievement/trophy system and better online components.

I will say 1/3-1/2 of an XBox One in actual real world performance.

Memory bandwidth is going to be the big problem for the Switch since I don't think they can realistically use high bandwidth eDRAM or eSRAM in a portable.

And even going with a 128-bit bus for the RAM is a problem potentially because that would increase battery usage and cost. My guess is they're making due with 25GB/sec 64-bit bus but leaning heavily on Nvidia's tiling approach to reduce bandwidth as much as possible with some faster memory caches.

If this thing is really capable of running PS4/XB1 ports, why in the world would you show a five year old Skyrim primarily in the teaser trailer? That Mario game also looked nowhere near a full generation leap past Mario 3D World, it looked very marginally better. Also Eurogamer's sources, which got everything basically right about the NS say 2-3x better performance than a Playstation 3 (not 4). 

Which for a portable system is pretty damn good. If you were expecting more than that, I just don't think it's reasonably possible with today's technology. 

You can't have a 20 watt portable, your battery will be dead in an hour. 

I think it will be close enough to XBox One that ports will not be blocked by processing power.

You can have XBox One ports ... you will have to accept

1.) Lower quality graphics/character models/lighting and shader effects/lower quality textures/lack of anti-aliasing. Developers will be have to be willing to put in some work to downgrade the graphics assets. Tegra X1 struggles with even PS3/360 ports unless a developer is willing to put in some real work (see Metal Gear Rising is awful on the Tegra X1, it runs way better on a 10-year-old XBox 360). 

2.) Lower frame rate

3.) 540p-720p resolution instead of 900p-1080p

Good for people who play a lot on the go. Not so good if you play a lot at home, you would be better off getting the XB1/PS4 and certainly the PS4 Pro/Scorpio version of pretty much any game.