wow, impressive work. all these links you managed to dig up.
the most common determination of companies in terms of size is market cap. it fluctuates, it has many humans factors built in and it's not perfect, but if you want to compare across different industries it has the advantage of simple, elegant, easy to understand and few people would spend time arguing against using it.
the mere fact that nintendo can even be mentioned in the same league as sony is impressive. that's really what most people are after here.
nintendo has what, 4000 employees worldwide? sony, what, 100,000? it's utterly ming-boggling. with all those divisions, movies, eletronics, hardware, computer, games, and all those added up can't match one nintendo. that, is what we gawk at. it's a david vs goliath, and david won.
can it last? who knows. sony is coming a comeback itself; because for a company its size, it's embarassing to have its market cap eclipsed by nintendo, and shareholders still aren't happy (though in the past 2 years its stock is up 70%). it's an interesting fight--a fight much tighter than anybody expected it to be.
the Wii is an epidemic.