I think that people fail to notice than whole Japanese market is relativly low right now. PSP is exception and it's doing fine becouse of Monster Hunter release but what about other consoles:
DS - last week it sold worse than in any other week in 2007 or 2008
Wii - it sold almost 50k which wouldn't be that bad if it wasn't with Mario Kart release that sold over half million copies. Last year weekly average for Wii was about 70k (I know it includes Holidays etc. but still with Mario Kart Wii should have beaten this). I think that Wii will go down and in a couple of months we can see a similar sales like in Septembe last year when lots of people where saying that Wii is on a downhill in Japan (but now people won't be saying that becouse all consoles will be down).
X360 - it just had the worst week this year and only few weeks last year had lower sales.