Wii U multilingual support
Solution 1:
I have a Swiss Wii U, which is set to English.
So far, every game I've bought and played has managed to display English text. However, not every game has to include English text. In the event that you buy a game without English text, the Wii U might possibly fall back to another language; on the PS3 that language was French for games bought in Switzerland.
Only the Nintendo eShop will not be available in English, unless you set your region to UK or US (or any other English speaking region). With Switzerland as my region, I had to choose between German, French and Italian as display language for the eShop.