Well, what do you expect to happen realistically? Already PS4 is at 4.2 million sales. I would say max cap for 1st year LTD is 20 million (including the 4.2 Nov-Dec.), and that is still an amazing number.
You expect it to sell like 28-30 mil by next December? It is completely unrealistic.
The Wii sold, what, 20 mil in first year? And I don't believe the PS4 is a Wii-like phenomenon.
At some point, the sales are probably going to slow to a crawl for a number of months before picking up steam again.
Again, it is all speculation.