MDMAlliance on 26 December 2015
I don't know if announcements of a new system do much to sales, but if it does then the PS4 could sell more. However, as things are, the 3DS is likely to sell more. There could always be upsets like the PS4 suddenly taking off big time in Japan.
edit: That's not to say that the PS4 hasn't already been doing things like that this year.
