Unless Sony commit huge mistakes or suffer from big supply problems, 16M should be at PS4 reach. For anything more, two conditions must be satisfied: 1) quite obviously enough demand; 2) Sony should have ramped up production in time (it could have already happened or being happening, Sony won't make us know before it releases official numbers).

The only unknown factor is the effect of new color in Japan, maybe it will do better than expected

ROFL, TLOU and watch dogs did boost hardware....1 remake and and watchdogs...Sales go up massively in the fall.. 600-750 k in SEPT?? ROFL the destiny bundle alone will push it WAY above that it will do 1 million in sept WW easy...please.  You expect ps4 to only do as well as ps3's holidays?? no.

I think he is out of the reality to expect only 600k in September, 600k is what does PS4 in a normal month without release.

I have the PS4 reaching between 18m-20m by Jan.2015

I guess not.. I've compltely changed my mind about the situation!

I think it depends entirely on how many PS4 consoles Sony can produce. It's a great first year for the PS4 and I believe that 16m is entirely possible at the end of 2014, IF Sony can keep up with the demand.

Now, my 11m prédiction with destiny FW is about to happen and it was even underestimated , since PS4 bundle in 2 days is about to titanfall bundle total for the year !!
http://www.amazon.com/gp/bestsellers/2014/videogames/ref=zg_bs_tab_t_bsar#3

Yes. But it highly depends on how the destiny effect goes.

Read the post above yours, Destiny FW alone will be enough, no need more ( but it will have more, it wont go back to 150k just like that, it will drop to 200k second week at the worst)