Japanese gaming publication Famitsu has revealed that Wii U will only be able to play games from its native region of purchase; meaning that it is region locked. Wii and 3DS are also in the same category but it is a shame importing is not a widely accepted component in gaming anymore.
I emailed Nintendo and asked if it was region locked a bit ago. The answer is the same but in more detail. Surprised no one else thought to do the same.