Here's what will be affected and when
Beyond Nintendo's regular maintenance of its online services, the company will be going through a brief period of emergency maintenance for the Nintendo Network this week. If you experience any odd behavior over the next two days, this is why.
From noon Pacific until 5:00pm today, the Wii U eShop, 3DS eShop, Wii Shopping Channel, and DSi shop will be impacted by the maintenance. Similarly, from noon through 6:00pm, the online features of Warriors Orochi 3 Hyper will be affected. Sorry, Jim.
Lastly, the Nintendo Network maintenance will hit Pokémon Black/White and Black 2/White 2 from 11:00pm through 5:00pm on Tuesday, January 29. That's going to be annoying for people who are still way into Pokémon. If that describes you and a Google search led you here, calm down by looking at some pictures of cuddly critters.