“Nintendo has already announced the Nintendo Network as a unified ‘network platform’ that delivers current and future online services to the Nintendo 3DS system and the upcoming Wii U console. These services include, but are not limited to, multiplayer online game play and the ability to download both add-on content and full games that are also available as packaged software. Further details on these services will be revealed at a later date.”
“However, there is no current announcement concerning a unified online ‘account system’ between Wii U and Nintendo 3DS, which suggests payment implications that Nintendo is not ready to confirm at this time. We hope this clarifies any misunderstanding.”
via The News from http://nintendo3dsfest.blogspot.com