It is a lifetime goal of mine to go skiing in Japan. I want to experience the snow that they get, the culture, the different trees, the FOOD. I might end up going more than once...
Norway sounds sick too, but it seems to me to be a lot of above tree line stuff, which I don't find as interesting. Yeah there are some huge mountains though, so if you were more into big mountain than deep pow and pow jibbing then Norway would be good. But it seems a little too similar to North America to justify an expensive trip in the middle of winter when Japan is an alternative...
Also I don't think Japan has much in the way of parks, if that has any impact on your decision. Norway seems to be good that way.