Aerys on 24 December 2013
Based on this thread : http://gamrconnect.vgchartz.com/thread.php?id=174808&page=1#
PS4 was 8th and is now 6th in 2013 best seller list, so it was a big shipment.
Predictions for end of 2014 HW sales:
PS4: 17m XB1: 10m WiiU: 10m Vita: 10m