@Montanah
700K isn't that much, when MKWii managed to sell 500K in Japan and possibly 500K in Europe, which both are much smaller markets, 700K + is very possible. GT5 might outsell that, but not by huge amounts, as you seem to think.
No, Mario Kart isn't a lot bigger in Japan. DS has about equal base in all areas, and MKDS has sold least LTD in Japan. The opening was, however bigger than in the others by 10% and 50%. That is most possibly because it launched much closer to christmas there, and therefore had an extra boost. There is no reason to believe that MKDS was bigger in Japan than in America/Europe.
As for the earlier games, we have a lack of data, but Japan was by far the smallest for MK:DD
Area/GC sales /MK:DD LTD sales /AR
Japan/ 4M/ 800K / 1:5
America / 12.7M / 4.2M / 1:4
Others / 4.7M / 1.9M / 1:2,5
This is unfair to America, as bigger markets tend to have lower AR, but it still shows us that MK:DD was by far smallest in Japan, and DS was pretty overall.
@Reggin
We now have "confirmed" that GT5 will CRUSH Halo 3's opening week, and actually come close to doubling it, by making about 7.5M.