Obviously "win" is a weird way to phrase it since there are so many different revenue streams and we don't always get a full picture. If we are talking in the traditional sense, i.e. console hardware sales, then I'm betting on Sony and the PlayStation brand. They produce too many excellent exclusives, have too strong of a presence worldwide, and with digital libraries being a real reason some might not switch I don't see Xbox keeping pace with PlayStation.
Of course a lot can happen in the next few years. We still don't even know all the details for these consoles.