Ok well I tried to calculate monthly sales based on momentum, generation declines and key launches that I am aware of and a few predictions on possible price cuts etc. With those numbers come these:
Wii:
18.1 Million
PS3:
12.3 Million
XBOX 360:
9.55 Million
Nintendo DS:
24.7 Million
PSP:
6.75 Million
I feel I may be a touch high on DS and a touch low on 360 but there are too many unknowns so I'm going with these predictions.