PlayStation 4: 1.7 million
Xbox One: 1.5 million
Here's why: as someone correctly pointed, the US$ 299 price for both consoles will be here for more days, so I believe that will have a big impact on sales numbers for the month. Another reason: the people who buy Christmas gifts at the last hour. It was predictable that US$ 299 would be back for December, so I think that there are some people waiting until the end of the month.