33-37 million is my prediction.

If we skipped FY Q2 2015 and went straight to FY Q3 2015, PS4 would be over 33 million. It sold 25.3 million as of the end of FY Q1 of this year. It sold 7.9 million in Q3 of last year, and, overall, PS4 is up YOY from last year, so it stands to reason that it's Q3 this year would be over 8 million. 

So, already, only 30 million is actually more unrealistic. 

Factor in what the PS4 will sell in FY Q2 this year (sold 4.8 million in 2014) on the backs of Arkham Knight (end of June, bleeding into July) and MGSV (September, and a Japan boost! Not just NA and EU, like Destiny last year) and bear in mind that PS4 is, again, up YOY over 2014, and 38 million by December 31st is not only more realistic, you can almost gurantee it will happen

no

??
q1 2015 down 0.6 million
q2 2015 up 0.3 million
q3 2015 we don't know yet, but ps4 sold 3.3 million last year

ps4 need to sell (in) 3.6 million q3 to be flat this year
also the p4 sold only 6.4 million units last holiday quarter. not 7.9
and the ps4 also did not sell 4.8 million units in fy14q2. they sold 3.3

way to much wrong missinformation in this post...
tl:dr ps4 wont hit 38million by december 31

They shipped 6.4 million last year in Q3........................and 3.3 million in Q2.....................

I believe the PS4 shipments this year will be some like 3 million this quarter and 7.2 million next quarter, so, around 35.5 million. i can see >36 million, but 38 million absolutely no. Only if they drop the price and doing litterally crazy with the deal and the marketing during this holidays.

... And they can actually, physically manufacture that many consoles.

For crazy deal, i talk about some insane promotion at XB1 style last year. And no, i doubt, Sony can't lose so many money like Microsoft can.

Me thinks 35m tops.

I think it's possible. Never underestimate the PS4, it has shattered everyone's expectations many times before. And this year is bloated with tons of AAA releases already.

I would say Yes.