Sony is content with having M$ winning the US by a small margin. Its the rest of the world that Sony is focusing on. The PS4 is winning Europe and the rest of the world so far and past sales show M$ has never done well in Japan, so I predict an all out onslaught when Japan goes live in Feb.
Sony will win the rest of the world and lose US for the next month or so.
Beyond Japan launch, Sony will aim supply back to the US and take that as well...............