Only 9M? You are pessimistic .
PS4 will be around 23M at least, likely 24M ans possible 25M by thé end of march, while X1 will reach at thé best 12M, so thé gap will be around 12M
Predictions for end of 2014 HW sales:
PS4: 17m XB1: 10m WiiU: 10m Vita: 10m