So, consoles usually sell around 50% of their annual total on the holidays. So I did some very simple math to see what can we expect:

PS4
4M by Dec 31, 2013
12M by Sep 31, 2014

8M Jan -> Sep 2014
8M Sep -> Dec 2014
16M - 2014 (Total)

20M - Total by Dec 31, 2014


XONE
3M by Dec 31, 2013
6M by Sep 31, 2014

3M Jan -> Sep 2014
3M Sep -> Dec 2014
6M - 2014 (Total)

9M - Total by Dec 31, 2014


Now my actual predictions are around 18M for the PS4 and 10M for the XONE by 31 Dec 2014. Why? Because XONE sales rely more heavily on the NA market where holiday sales grow the most.

Agree with you prediction.

I agree more with the first number...

And this gem the PS4 will sell more on holidays because this time it own US (where the biggest boost happens).

My prediction continue the same I did a year ago with PS4 and Xbone missing by little the 20m and 10m target respectively... so 19.5m and 9.8m.

I think Oct-Dec won't be more than 6 million for Ps4, so if 11.8 M is the current sell through that means it will fall just short of 18 million at best. I think it will be more like 5 million. I don't think the game library is there to get more than that. Next holiday though...

I finally did the math, and I can honestly say that I think the PS4 will be at 21m by the end of this year with the X1 being at 9m.

XB1 figure too low, XB1 will have about 1m in the channel by the end of the year, and these figures suggest you think they'll ship 2.5m~ this Q. They just shipped 1.8m~

360 shipments in Q4 were never less than double Q3.

This last phase is exactly what VGC does to predict sales... use old 360 and PS3 data... that is why it is having big adjustments constantly... this gem is different.

Your Xbone prediction is a bit odd to be fair.

Don't they almost always sell more in their second holiday if they're a popular console though?  4m in 1 and 1/2 months before now it will do 6m in 3 months?

Nah it's fine, if you wanna believe it's gonna do similar results in Q4 so be it, you'll be wrong though.

Also, MS have said they anticipate higher shipments for XB1 in Q4 compared to last year. They must have a good idea how much they plan to ship right now so close to the holiday.

This isn't about shipments though. Shipments depend on what the console market wants/expect to sell, previous manufacturing contracts, possible overstuffing since it's the holidays and then slowing down the next quarter, etc.

This is about sell-through.

It's truth that consoles sell more their second holiday than their first, but remember that most consoles also suffer from severe manufacturing problems their first holiday, it wasn't as bad with the PS4/XONE which is why they had unprecedented launchs. However I think PS4 selling 6M on the holidays is a given, maybe more.

Of course MS knows what they intent to ship better than anyone, they call ship whatever they want to some extent (limited by manufacturing capacity, storage, retailers will to take units, etc). The problem is what they'll manage to actually sell to customers, if their LTD by Dec 31, 2014 is over 10M I would be extremely surprised.