It needs 1.2 million+ ((xb1 sales x (ps4 sales x2)) if PS4 should sell above it baseline for 4 week in Japan assuming 10k gain rest of world and 300k more sales in Japan next 4-5 weeks, give xb1 100k boost over the next 4 weeks for Titan fall the PS4 will need about 1 mill to double XB1. With Japan base lining 15 to 20k or so I could see the PS4 gaining 35 to 45k a week. Or 150 to 200k a month. At this rate the PS4 would double the XB1 by the 1st week of NOV. I think the PS4 will not sustain this through the holiday it will sell a lot but the supply won't be there to double what should be solid sales for the XB1 during CMAS. I think sometime in the middle of 2015 the PS4 will double XB1 and won't look back.
obviously if MS decides to through money away and sell the XB1 at what would be an 70 dollar loss this wont happen unless the PS4 get a must have smash hit system seller.
End of 2009 Predictions (Set, January 1st 2009)
Wii- 72 million 3rd Year Peak, better slate of releases
360- 37 million Should trend down slightly after 3rd year peak
PS3- 29 million Sales should pick up next year, 3rd year peak and price cut
