Don't lose or damage your console. Your Nintendo Network account may be at risk...
Though the Wii U's been a sellout in North America, its launch wasn't without problems. Many buyers found themselves with a bricked console after shutting it off during the enormous day-one five GB update for the Wii U's online content.
Now, there's another caveat that Wii U owners should be aware of. Nintendo Network accounts, required for Wii U online play, are tied to one console, meaning that should anything happen to that console, owners will also lose their account and anything tied to it. Currently, the Wii U supports up to 12 accounts that will be locked to the console after creation, meaning that buying up a used Wii U means losing account slots on the console.
Wii U owners will be disappointed to find that they won't be able to play at a friend's house unless they also cart over their console, since this lockdown means that accounts, once tied to a console, can't be logged in on other consoles.
However, this issue is only temporary, as Nintendo has declared on the Wii U support site that: "In the future, you will be able to use your Nintendo Network Account with future Nintendo consoles and other devices, such as PC's."
The company's statement didn't include a window as to when this would happen, so for now, it might be wise to keep your Wii U stashed well away from any potential damaging elements, lest you lose your precious Nintendo Network account.