So, I'm still kinda confused as to what the NNID does.

So it finally gives me an account like a live or PSN account that I can use to sign into. That part I get.

I also know that the 3ds and WII U have a combined eshop wallet and that consoles can be linked.

So now, besides that, what else does it do?

Does it finally allow for digital games to be tied to an account?

You can log into Miiverse with the same ID from both devices and share balances, but purchases are not tied to your account. Which is a shame, Nintendo need to sort this out!

Also I'd like to see Cross-buy across the eShop (Virtual console would be a good starting point).

Gahhhhh, this one thing is basically keeping me from buying a Wii U because I know I will want to buy games digitally -_-

For multiplayer, can I give someone my Nintendo ID instead of a friend code?

@jneam: Nintendo ID is used for the Wii U, and Friend codes is for the 3DS. At least Nintendo is learning as they go on but at a really slow pace.

Alright, that's some good news!

Still, I have a 3DS, sucks that it's still friend codes.