Ah that's good to know, so that means it is technically possible, unless they had to buy a licence from Nintendo.

Still, I wonder why we haven't seen dozens of clones? For all previous consoles, there were lots of third party controllers as it's a quick money earner, and for something as successful as the Wii, I would have thought there would be more. There are plenty of third-party jackets and balance board bags etc. after all.