When will the PS3 pass the 360 in monthly sales in the USA?

[rage4dorder]

I think it's interesting to see the aligned launch graph ( http://vgchartz.com/hwcomps.php?cons1=Wii&reg1=All&cons2=PS3&reg2=All&cons3=X360&reg3=All&align=1 )
where the PS3 is almost at exactly the same spot as the xbox360.

I don't think it will increases sales dramatically until it gets to the $350-$425 price range (9-12 months from now?).