Actually, system DOES imply hardware. When speaking of the videogame market, system is synonymous with console. I.E. Super Nintendo Endertainment System.

I like a tablet as a new product. Perfect for amiibo, can stream to tv, is used for nearly everything nowadays. Could open up a whole lot of innovative software (not really innovative, but innovative for a gaming platform). A separate dongle would be perfect. WiiU integration would be great too.

I'm pretty sure Zayn is going to return and take the title from Owens at some point.

I don't know what this means

I actually wrote part of this in another forum, but here goes:

To me, a third pillar could only be a tablet. It made sense: Nintendo specific mobile games still on Nintendo's HW.
But since no announcement was made, then it most likely isn't it.

What i think NX is.
It's both the handheld and home console where both play basically the same games/share the same library.
This is what i have been thinking for a long time. Yet, because of this conference i can't shake the feeling it's something more.

I don't know if it's HW related, OS related... I just feel that there's more to that "brand new concept" than just the controller being different.
And when Iwata said that this mobile development situation affected the HW development for next gen i just knew that there was something more.

I can think of a few things:
1 - He's actually talking about sharing the same library between systems;
2 - It's just OS related and there's interaction between the mobile side and gaming dedicated devices;
3 - This new machine will interact with QoL to help modify the game according to your physical state , thus adapting it to you and making it a unique experience every time you play;

And now for the best part:
Going back to Iwata's comments in a Investor meeting: "In contrast, the number of form factors might increase. Currently, we can only provide two form factors because if we had three or four different architectures, we would face serious shortages of software on every platform"

4 - NX is not your conventional gaming machine - or at least just that - and you get an extra form that allows not just Nintendo games, but combines a gaming device + Android console + Steambox into one single HW device or devices (handheld included).

Nintendo's consoles will have a controller; Android consoles have a controller; Steamboxes will also use a controller.
And guess what! All of them share the exact same controller layout.
Now, in terms of OS. Doesn't XB1 juggle 3 OSs? So if Nintendo can't make a OS that allows for all, they can have all of them too.

Wishfull thinking?

The ideology of Iwata: Nintendo having a mobile gaming future. The last transitional console, NX, before going full mobile.

His goal is to make an N-phone and be full digital.

Beware, his reign of terror is only at its half way point. The beginning was embracing the causal's with the Wii, next is mobile gaming. He has destroyed Nintendo beyond repair.

Actually an holographic display wouldn't be too far fetched. There were some holographic 3D prototype phones at CES2015, and Nintendo just spent 100 million $ on some unknown tecnology. http://www.gonintendo.com/s/227800-nintendo-spends-100-million-on-mystery-acquisition

Based on Nintendo's situation with the Wii U, this Is going to be the successor to Nintendo's home console.

It will most likely be significantly more powerful than the Wii U and have much more ram.
It will probably launch in late summer to fall 2016.
It will likely interact with other devices, in a similar way to how the Wii U interacts with the gamepad.
Whatever the controller, it will likely not be as bulky as the gamepad, although there's really no indication as to what it will be, but it will likely have a touchscreen of some sort since that will probably be a requirement in all future consoles eventually.

Supposedly, they were looking at free-form screens, not holo. Holo would be too expensive for nintendos historical strategy

They have it in the same picture as the wii u and 3ds so it's unlikely it will be a successor. It will be a successor in the technological sense, but not in the physical