This is a bit depressing, I predicted 21.5-22.5M just 2 months ago.
Just to put in a bit perspective to this post (which I will make my prediction from).
In the same period last year, Ps3 sold 3050K, it needs around 100K more than that this year.
I'm thinking Ps3 will end in the 19900-20100K range, seriously. It is going to be a hell of a close.
http://www.vgchartz.com/games/userreviewdisp.php?id=261
That is VGChartz LONGEST review. And it's NOT Cute Kitten DS