Gamasutra just released another article following NPD results in which they analyzed software sales in the US per platform since the beginning of the year.
Here it is : http://www.gamasutra.com/php-bin/news_index.php?story=25740
First thing you notice is the following :
2009 software sold is up compared to 2008 for both PS3 and Xbox360.( +4 millions for 360, +3 millions for the PS3)
It is the same for the Wii.
For hardware we have :
Wii : -1.150k units
PS3 : -180k
Xbox360 : +260k
So the majority of the decline in gaming revenue is actually a decline in Wii related revenue and the revenue coming from others console actually doesn't seem to have decrease much if at all....
Depending how the holydays go, it's actually very possible that both PS3 and 360 related gaming revenue will be up in 2009 compared to 2008 in the US..