My guess is that it will be unique in that Nintendo will offer some stuff like eshop and global network and developers will create their own systems for their games.
Something similiar to Ghost Recon Online, Ubisoft said that it will come with a special program to keep u always connected with other ppl from Ghost Recon Online such as chating, video and picture sharing, game invites, it's own gamerscore and so on.
That would be awesome imo since devs would have opportunity to actually improve on the already established standard.
As far as Nintendos main network (that will power it all) goes i think they will seek support from more than 1 company.
Online gaming is future due to incredible replayability and they know that they need to do it right this time.
I would not be suprised to see Zelda MMO either but not like World Of Warcraft cra* but engaging online co-op rpg-adventure with Nintendo style story (something like Four Swords Adventures just a lot bigger and more awesome).
