Nintendo's eShop is back online for all systems following repairs to many online services that had failed over Christmas. Nintendo gave the all-clear moments ago.
The eShop had been on-and-offline for some platforms and regions since Dec. 25 as the company worked to resolve the problem. On Facebook yesterday evening, Nintendo said the outage had been caused by a "one-time surge in demand" over the holidays, compounded by an influx of new Nintendo Network accounts, and the conversion of existing 3DS account information to Nintendo Network accounts.
The Nintendo Network ID became a single unified account for all platforms about a few weeks ago; before then, users of multiple devices had their purchases tied to the console or handheld where they made them. The eShop for 3DS and Wii U, along with all other core online services, went offline sometime during Christmas, which prevented users from creating Nintendo Network IDs. It was up and down intermittently since then.
Of note, the company said it would have more information later about the launch of the Pokémon Bank and Poké Transporter apps. These companion apps for Pokémon X and Y were supposed to launch on Friday but were held back because the high demand for them would have made the traffic problems worse.