the reason xbox doesnt get more support in japan is that it is a western system that caters more to western gamers, games that do well here (ie, halo) dont do so well in japan b/c of their taste in games. it has nothing to do with "forign devil" nationalism, its just a different society with different tastes.
but xbox is and should stay in the 3rd spot, with the rev coming in a close second, ideally the ratios should be 50/40/10 with ps3 in first and xbox in last.
xbox brings almost nothing origional to the table (neither does the ps line, but their 3rd party support/diversity makes it the best)