My impression is that it's readily available (but selling well) all over the world, except for Japan and the US.
My guess is that people are waiting for a Mario game and that demand will increase once SPM gets out. And of course SMG, it will be crazy.
Oh, and a swedish store actually used the box art from The Gods Must Be Crazy to illustrate that they got Wiis in stock a few months back :) But now it seems they have plenty in store every time I check.