It took long enough, and it’s part of an update coming in December—you will finally be able link your 3DS and Wii U and their eShop balances together by signing into a Nintendo Network account on your 3DS. But I don’t understand Nintendo’s reluctance at forbidding multiple 3DS/Wii U consoles from using the same Nintendo Network ID.
Nintendo expressing this in support documents and marketing documents make the matter feel like a tacit acknowledgement that they believe nobody needs to use their Nintendo Network ID on any other device. Or, that nobody will own more than one 3DS console, or more than one Wii U console.
And I can already think of some legitimate use cases that using a Nintendo Network ID on more than one device can have.
Take a look at Apple and the iOS/Mac App Store. You could use your Apple ID on up to five (or “every Mac you own” for the Mac App Store) devices at once. Want to share a game with the wife/partner? Or your kids? Buy once on your Apple ID, and use iCloud purchases/iTunes to download them onto your kids’ iOS devices. Or maybe you’ve just bought a fun universal app on your iPhone and would like it on your iPad—Automatic Downloads will have sent it to your iPad already.
The same cannot be said about your kids’ 2DS/3DS consoles. Want to share a game between multiple consoles? Prepare to whip out that credit card and spend on that game multiple times. Or maybe a game you’ve bought from the eShop would look better on your 3DS XL. Can’t play it on both at the same time, so you’ll need to do a System Transfer.
It also happens to be that you can sign into Miiverse on every other device that you own—sign in on the web browser or sign in on both your iPhone and iPod touch. Want to do that on a Nintendo 3DS or your friends’ Wii U? That’s a no-go.
This only strikes me as another consumer-hostile decision made by the heads in charge. And it also makes me wonder as to the exact point of a Nintendo Network ID.