4 million PS4's sold (through to customers not "shipped") worldwide during November and December.
NPD numbers for December should be out in a week or two. Color me surprised that Microsoft actually raised the price back up on the Xbone after their holiday discount.
http://www.gamespot.com/articles/ps4.../1100-6424475/
Sony has now sold more than 18.5 million PlayStation 4 units worldwide, the company announced today in a Japanese press release translated by Reuters. This is up from 13.5 million at the end of October 2014. The new milestone counts consoles sold up to January 4, 2015.
It's possible PS4 sales could have been even stronger if it weren't for supply issues in Europe during Christmas, according to PlayStation president Andrew House. The executive also admitted that PS4 sales conditions were "tougher" in November due to the Xbox One price cut.
By comparison, the Xbox One had shipped 10 million units as of November. Microsoft has not provided a new sales tally since. We'll have that information for you as soon as it becomes available.