My guess:

- Common wallet with frequent user rewards (buy a Mario 3DS game, get 1000 coins for Mario mobile F2P game etc.)

- Introduction of "achievement/trophy" system

- Amiibo sharing

That sounds alright. Im also hoping they have a subscription based service similar to PS+. If somebody is subbed to this program on mobile and sees free VC games or an old retail release along with exclusive discounts on NX they are more likely to go buy one.

So what happens with NNIDs then? Are they done?

I'm guessing this will launch for next year (fall 2016).

Also they don't say if its a console or portable, Iwata just called it a "platform".

This is the direct quote:

As proof that Nintendo maintains strong enthusiasm for the dedicated game system business, let me confirm that Nintendo is currently developing a dedicated game platform with a brand-new concept under the development codename “NX.” It is too early to elaborate on the details of this project, but we hope to share more information with you next year.

Likely expanding them to this new system across multiple devices such as NX and Nintendo's mobile platform

I'm not too sure I like it, but since it will most likely be required to play Wii U games then I'll do it. But they're going to have to show me something with this new setup they're working on.

Nintendo Fusion is coming, all the details were leaked long ago:
http://vr-zone.com/articles/rumor-nintendo-fusion-nintendos-next-gen-hardware-solution/70439.html

Oh wow! Lots of Nintendo news this morning! I wonder how they'll handle the mobile/PC games though; a Mario platformer would suck on mobile. Maybe they're some kind of mini games that ties in to the bigger game released on a Nintendo console? Like, if you play Zelda at home and then need to go somewhere, the mobile game could mean that you get to still play your Zelda game, only in quite a different matter, and not with as advanced features?

if its a new home console then they're keeping to the 5 year cycle. Announcement at e3 2016(reveal), release in 2017

Sounds like you are talking about a modern Nintendo version of this =P