I have no idea if this was ever brought up, but in this Venture Beat article citing Börse I just posted, they peg worldwide sales of the PS4 at 16.1m and the Xbox One at 9.1m as of November 2014.
We already know that the PS4 is at 18.5m as of January 4, 2015, so that would put December sales at 2.4m.
This would also mean that the Xbox One is most definitely over 10 million as of January 4, 2015, as December NPD only would put it at 10.4 million.
Those are chartz numbers. Discard them and just focus on official numbers.
That is incredible, how two consoles are pretty much irrelevant in such little time. Going to be interesting to see where the PS4 is at when the XB1 reached 1 million in Germany, could see PS4 at 3 million minimum.
PS3 is currently at around ~4.2m so it's very possible that PS4 will exceed that, certainly I can see PS4 exceeding 2 million in Germany before the end of this year.
And the UK should have a 2 million announcement before the end of Spring.