Incredible prediction.
He is expecting PS4's average to go up 3k a week from last month, despite Madden, 3 months worth of Destiny preorders, that on Amazon has been above any Xbox sku every hour since it was announced, a big marketing campaign for the biggest game of the year so far and the fact that September is always bigger than August anyway.
I think he is at least under-predicting PS4 by 100k