Dying out? Even if it doesn't peak this year it will still be up yoy compared to 2010. It's most certainly not decreasing. Not to mention the fact it's possible that it will end quite close to the Wii's 2009 performance (price cut, NSMBWii). Would you say that Wii was 'not a big deal' in 2009?

You might be right by calendar years, but in absolute terms, the period from September 1 2009 - Aug 31 2010 or so saw Sony sell 2.3m PS3s in Japan within 52 weeks (PS3 Slim, FFXIII lift, 10,000 Yen price cut). I don't see PS3 ever matching that again in Japan. Same thing happened in the US - PS3 did 4.9m in the US from Sept 2009 - Aug 2010, and has since fallen to 4.3-4.5m in a 12 month period.

I have a hunch that Vita will eat up a fair bit of PS3 hw support going forward in Japan as well. Some will prefer to have a PS3 in their hands rather than in their homes which will lessen the need to purchase a PS3 by quite a bit from Dec 2011 onwards.