Well this is no surprise, Nintendo has region locked their consoles since the NES so why would their newest console be any different. According to g4TV.com and CVG

Nintendo has decided to region lock the Wii U, which is a long standing policy for the company that dates back to their first ever home console. There are ways around the region lock system, but at face value it means that a game released in a certain region must be played with a console made in that same region.

Microsoft and Sony technically region lock their consoles as well but there is one key difference, Sony and Microsoft allow developers and publishers to choose whether to region lock individual games. However, Sony´s newest handheld, the PS VITA is region free.