The Japanese have always avoided foreign brands, this is why the PS3 is doing better than the 360 there whereas elsewhere the story is completely the opposite.
Western consumers seem to go for what they perceive as the best product - sometimes that's the same as Japan, i.e. the Wii, sometimes it's different i.e. the 360 in the west, the PS3 in Japan. What this does mean however is that as Japan loses it's hold in the tech sector which it is in some areas Japan is becoming increasingly irrelevant as a measure of success and I'd argue it's largely irrelevant in this case.
With just short of 335mill people in North America, 800mill in Europe, Japan's relatively small 120mill are again another reason for Japan's irrelevance in measure. Countries like China, India and many south American countries are often following the Western nations trends in purchase of consumer electronics albeit it to a lesser extent due to the relative poverty however of course this poverty is decreasing in these nations compared to much slower or even negative growth in the richer nations of the world.
To put simply then, I'd say it matters little more what's happening in the Japanese market than what's happening in the Spanish, the French, the Canadian or even the British market because in these nations alone the format wars are not going to be won. Japan's biggest problem is that it's strong patriotism to home brands risks leaving it as an anomaly rather than an example of trends should any of the home brands such as the PS3 fail to the 360. It's foolish to treat Japan with the same importance as the whole of North America or Europe nowadays as many sites seem to.