It would seem that 12-12.5 million PS4's sold through by the end of September is highly likely now, I doubt retailers would have more than a million sitting on shelves, especially considering this was Destiny's launch month and the white PS4 came out.
If the system has sold 12.5 million, that would mean PS4 has sold 8.1 million units in 2014 (4.4 million in 2013), if that accounts for 50% of the year's sales then 20.6 million by the end of 2014 isn't unlikely now. I expect shipped totals to be at 21 million by the end of this year, which wouldn't be unreasonable considering Sony managed sell more than 4.4 million by the end of 2013, they would have to have shipped in excess of 4.4 million between August and the end of December, or more than 1.1 million a month at the beginning of their production cycle.
Averaging 1.4 million shipped a month across 15 months doesn't seem unlikely IMO.
No doubt Sony will have no problem selling that number, the demand will be huge this holiday.
