Nintendo's skyrocketing stock price has done more than just make former chairman Hiroshi Yamauchi the third richest person in Japan, it's also, naturally, done wonders for the company's market value. Today in Japan Nintendo briefly broke into the top 10 most valuable companies in the country, bumping Sony down to number 11 for a few sweet (for Nintendo) moments. And we're not talking SCE here, we're talking about the whole consumer electronics juggernaut that is Sony, taking a mild beating from a games only manufacturer. By the end of the day, Sony had returned to its former spot on the chart, and analysts are starting to express caution in regards to Nintendo's stock, since they think much of the company's future growth has already been factored in. We'll have to wait and see if Nintendo can keep Wii sales as brisk going into this holiday season, there sure isn't any end in sight for the DS.