Image, culture, libray, approach, online focus, plus probably others.
I think image is a key ingredient though, both going back to the Xbox, the seeming focus on FPS, the apparent HW issues, the focus on online and the link to Okatu (spelling?) titles.
I wonder whether MS would need to sacrifice their image somewhat in the West to change it enough to see success in Japan? This might help but I doubt MS will be willing to do so - my view is unless the Japanese market changes - seems unlikely - or MS changes its approach significantly just for Japan - seems unlikely - the brand will struggle to ever be more than niche.
Japanese platforms just seem to have an image and approach the enables them to more readily succeed globally whereas MS approach seems to limit them to English speaking Western countries such as US, UK, Australia, etc. The combined US/UK sales, for example, represent a huge chunk of 360 sales vs the much more spread percentage sales of Wii and PS3 globally.
Try to be reasonable... its easier than you think...
