Is it possible for PS4 to cross 17 million mark by 2014

[archbrix]

COX said:
So if the Ps4 sales 15M by 2014 it means that it may pass 20M during its peak year.

Nah.  Remember, 15m by the end of 2014 is including the 4m+ from the PS4's launch and holiday of 2013.  Personally, I don't think the PS4 will ever have a 20m+ year.