PlayStation 4 without a doubt will hit 15 million first. It should hit it by the end of the year no problem. The Xbox One will get to 15 million second. With all the bundles Microsoft is trying to not fall to far behind the PS4, so I expect it to hit 15 million in the first half of 2015. The Wii U will hit 15 million third, but with current sales not until the end of 2015 at the earliest.