You can see the more detailed original analysis here:
http://gamrconnect.vgchartz.com/thread.php?id=178341&page=1

However, In addition to all that, quick analysis between the first and last halves of each between 2007 and 2012 inclusive for PS3 and X360 showed an almost exact doubling of sales in the second half of the year compared to the first, though with a variance. The jump was smallest in 2008 with +83% while largest in 2009 with 125%.

So this means, based on historical data, the combined XB1 and PS4 sales are likely to increase between 83% to 125% from 6.1 (4.2 + 1.9) in the first half of 2014 to a figure between 11.2 and 13.7 combined, reaching up to total of a figure between 17.3 to 19.8 million annually.

Based on the current trend, around 67-70% of those sales will belong to PS4, and the rest to XB1, while individual figures are as follows...

2014 Annual Sales
PS4 : 67-70% of 17.3 - 19.8  million = 11.6 to 13.9
XB1 : 30-33% of 17.3 - 19.8 million = 5.2 to 6.5

Cumulative Sales by the end of 2014
 - (add 2013 end sales)
PS4 : 11.6 to 13.9 + 4.1 = 15.7 to 18 million
XB1 : 5.2 to 6.5 + 2.9 = 8.1 to 9.5 million

In short, although the ranges somewhat move in either direction, the core estimates don't change
PS4
Original estimate : 13.7 - 17 mil
Half2 / Half1 estimate : 15.7 - 18 mil
Halves analysis update :  3.4 / 3.49 * (15.7 - 18 mil) = 15.3 - 17.5 mil

XB1
Original estimate : 6.3 - 9.8 mil
Half2 / Half1 estimate : 8.1 - 9.5 mil
Halves analysis update : 3.58 / 3.49 * (8.1 - 9.5 mil) = 8.3 - 9.7 mil

So we can now confidently say, by the end of 2014

PS4 will sell around 16-17 million
XB1 will sell around 8-9 million

The non-linear PS4 / XB1 sales regression analysis also yields a similar result, producing a ratio around 1.92 for the 2014 end, implying PS4 will have sold 90% more consoles (16.5 million / 8.5 million = 1.94). It all makes sense.

--------

UPDATE

Market Share Trends including All 8th Generation Consoles

After some persistent demand, here you go, ...

Cumulative Market Share for all consoles in 2014

PS4 : Up from 34.3% to 42.6%

XB1 : Up from 23.9% to 24.3%

WiiU : Down from 41.9% to 33.1%

Annual Market Share for all consoles in 2014

PS4 : flat around 58.5%

XB1 : down from 34.0% to 25.6%

WiiU : up from 10% to 16%

Expected Trend in 2014 based on Current Data

PS4 : Expected to increase from 42.6 towards 58.5%

XB1 : Expected to stabilize around 25%

WiiU : Expected to decrease towards 20% range

----------

Halves Regional Analysis

Assumptions :

1) non-English speaking countries' surges are more evenly distributed
2) English speaking world takes up 50% of the world console market share
3) The quantities sold double from first half to second half on average
4) X360 and PS3 sold at equal quantities
5) Market Shares are rounded to 60%-40% in English speaking world, and 40%-60% in non-English ones

In the earlier gen, X360 had a roughly 60% share versus the 40% of PS3. Let's say the surge gives an extra 50% boost (on top of the usual 50% boost everywhere). The surges between 2 halves are distributed more evenly in the non-English world compared to English speaking ones. Basically this is what happened in the 7th generation:

7th generation annual sales fluctuations (on average, in percentages)

X360
English : 60 surges to 120 => total 180 (60%), DOUBLES
n-English : 48 surges to 72 => total 120 (40%), 50% INCREASE
1st half sales :  60 + 48 = 108
2nd half sales :  120 + 72 = 192
Increase factor : 1.78x (+78%)

PS3
English : 40 surges to 80 => total 120 (40%), DOUBLES
n-English : 72 surges to 108 => total 180 (60%), 50% INCREASE
1st half sales :  40 + 72 = 112
2nd half sales :  80 + 108 = 188
Increase factor : 1.68x (+68%)

Now, let's repeat the same scenario with due market share adjustments (in 8th gen)

Assumptions
1, 2, 3) The same as above
4) Quantities at this stage are irrelevant, dealing with percentages
5) Market Shares are rounded to 40%-60% in English speaking world (favoring PS4), and 25%-75% in non-English ones

8th generation annual sales fluctuations (on average, in percentages)

XB1
English : 40 surges to 80 => total 120 (61%), DOUBLES
n-English : 30 surges to 45 => total 75 (39%), 50% INCREASE
1st half sales :  40 + 30 = 70
2nd half sales :  80 + 45 = 125
Increase factor : 1.79x (+79%)

PS4
English : 60 surges to 120 => total 180 (44%), DOUBLES
n-English : 90 surges to 135 => total 225 (56%), 50% INCREASE
1st half sales :  60 + 90 = 150
2nd half sales :  120 + 135 = 255
Increase factor : 1.70x (+70%)

Comparison of Increase factors
X360 : 1.78
PS3 : 1.68
XB1 : 1.79
PS4 : 1.70

Seems like the increase factors are virtually unchanged but the gap between PS4 and XB1 has slightly decreased. As long as Xbox leans more on the US side of the equation, the increase factor will benefit them relatively more . So in the main analysis, the expected values for PS4 may be a bit lower (more in lines with the original estimate, instead of shift up), and a bit higher for the XB1 (but still within the given range). The due adjustment has been made under the label "Halves analysis updat", which are 3.40 / 3.49 for PS4 and 3.58 / 3.49 for XB1  (shifts PS4 down a bit, XB1 up a bit).

Interesting read. I'll have to check this thread frequently.

Can you break it down by region ? PS4 is dominating Europe so much i wonder if Holiday sales there will be greater then NA.

Also how do 4-1 sales in Europe effect overall sales breakdown ?

current trend doesnt include tier 2 countrys for xbox 1.

until they sell zero units there and the rest of the world stay the same, this figure has to decrease...

if they sell some units there, the rest of the world has to increase for the ps4 marketshare to stay at 67-70% for ps4

Note : I have no intention to spam or whatsoever, I am just trying to avoid typing the same thing again on another thread, but here you go, my reply:

---
2014 First half ps4-xb1 & ps4/xb4 market share are as follows:

Cumulative : 63.7% - 36.3%,  PS4 / XB1 = 1.76

Annual : 69.5% - 30.5%, PS4 / XB1 = 2.28

There is nothing that in the statistics that suggests XB1's share will rise further. It has gone down considerably since last year, and the only thing that stops it from going further is the price cut.

Market share of XB1 (between XB1 and PS4 only) in the first half of 2014

Cumulative : Decreased from 41.0% to 36.3%

2014 only : Decreased from 36.6% to 30.5%

Also the current annual 30.5%, which is smaller than the cumulative 36.3% suggests that the market share will keep decreasing below 36.6%, albeit the price decrease may reverse it a bit. So yes, 30-33% range is VERY LIKELY.

So... about the Wii U... do you think we could we get an estimate for that tiny console too?

-edited-

Seems like i was wrong, sorry!

xbox 1 will release in china ps4 dont

frontloaded tier2 sales will come for xbox 1 in the second half of 2014, while frontloaded tier1 sales  (both ps4 and xbox one) already included in frist half of 2014.

and as u can see the xbox1 dropping  marke share from cumulative to annual, inital realse sales are very important (at least in the very beginning of an generation)

it wont be big, becaus these countries arent the biggest markets, but they matter. even only  2,5% of 20m are half a million consoles.

just do the math again in oktober and we will see if something has changed.

edit: but maybe the ps4 destiny and white console bump will be to big and negate all of the tier 2 inital sales

I don't think that you studied the yearly surge that M$ sees in the November and December period.  IF you have applied the same increase percentage to both the PS4 and the XB1, your data will be probably wrong.  Historically, the 360 sales increased higher at christmas than the PS3 did by a decent margin.  In almost every year, the PS3 outsold the 360 all year long and that was washed out by the 360's increase in sales at the holidays.  M$ breaks the bank at the end of the year to get market/mindshare.

With that in mind, I am not saying the PS4 won't outsell the XB1 handily, but I am saying that the market share percentage won't be as wide as it is today.

yes ur right

x360

october-november

november - december

ps3

october - november:

november - december