Wii U is Region Locked
U software region locking has been confirmed, as recently stated “software not sold in the same region cannot be played" by Nintendo in a Japanese game magazine. This means imported games will unfortunately not work, unless you own more than one system from different regions such as North America, Europe or Japan.
Nintendo has region-locked almost every system, spare only the DS
, so it's not much of a surprise. Bypasses, although frowned upon by Nintendo and illegal have been developed for pretty much every region-locked system before, so the Wii
U will probably have one eventually, though I'm not encouraging their use. It seems we'll just have to wait to get most titles released in our respective region, though some games aren’t sold out of Japan. Hopefully, this isn't much of a problem for most of you. Source 1