I think when the PS3 price is around 250 it will sell more than the Wii right now.
And I think too the Wii 2 will arrive before the PS4 so maybe the PS3 still has one year or so of exclusive sales to reduce the gap.
As for the 360 ,its obvious sooner or later it will pass it.But its getting more time than I thought ,mainly because the weak japanese sales.If the PS3 was around 4-4.5 millon consoles in Japan as it should wasnt the japanese hardcore market in such a crisis we could expect the PS3 to overtake the 360 as early as this year.With such slow japanese sales it will have to wait until next year.







