I took the sales increase / decrease each week after black friday for each console from last year and applied them to the black friday sales for the Wii / 360 / PS3 this year to extrapolate sales through 12/31/11. Here is what the year end total for each console ends up being (globally):

Wii: 96,420,562
360: 65,440,090
PS3: 60,581,794

That would mean the 2011 sales for each console would be:

Wii: 13,950,375
360: 15,128,867
PS3: 14,320,514

360 would have outsold PS3 in 2011 by 808,353.

The five weeks after black friday last year sold 5.09 times as many units as the week of Black Friday for the three consoles combined. If we assume the same and assume the same relative sales gap as we saw Black Friday (in which the 360 outsold the PS3 by 411,587), we would project the 360 sales gap over PS3 in the next five weeks to be 5.09 x 411,587 = 2,095,964. The 5.09 is based on the combined sales of the Wii / 360 / PS3. If we take the individual sales trends for each console and apply them to each consoles totals of Black Friday this year, the sales gap for 360 would increase over PS3 during the next 5 weeks by 1,800,625, which is the stat that I thiink the sales will be closer to (and the stat I am using to get the figures above).

The two weeks before Christmas each actually sell more units than Black Friday. The two weeks prior to that sell almost as many units as Black Friday (about 80%). Considering those statistics, 360 has a VERY good chance of passing PS3 for 2011 by year end if the relative sales gap we saw between the two during Black Friday remains in place. The 360 is less than a million behind now and only needs about 2.5 times the gap it had on PS3 during Black Friday to overtake the PS3 sales. I think 360 will beat PS3 in 2011 sales rather handily when all is said and done.

The extrapolation of sales actually projects the 360 to take over the 2011 sales lead before the week of Christmas (after the week ending 12/17/11).

There's two problems with your assessment, though.  For one, this year's Black Friday was much larger than last years because instead of deals starting early Friday morning, they started Thurs night at 9/10 PM.  This lead to a lot more people going out to take advantage of the Black Friday deals, ones who normally would choose sleep over going out early Friday morning.  Which, in turn, will mean a lot more people got in their holiday shopping during Black Friday and will probably cause a slight drop off in the sales that would have gone to the weeks right before Christmas. 

And second, the 360 had plenty of stock for the month of December in 2010.  This is because MS moved the shipments that were supposed to go out in early Jan to December, to make sure they had enough stock.  The shortages were mostly felt in January - early February. 

Also youre basing yourself on the projection that Sony wont reach its 15 million units sold this year quota, wich Sony keeps saying theyre on track to reach, so Id say your extrapolations are a little bit "extrapolated".

Lets see what the post Black Friday week numbers are and if youre right Ill come here and give you props but I dont think you will be.

The 360 shortages were felt the week before Christmas and after for sure. I remember it distinctly.

And this Black Friday was no different than past year Black Fridays. There were deals Thursday night last year as well. I have no idea why you think this Black Friday was any different than in year's past.

This is what the extroplation says the sales should be for 360 each of the next five weeks:

884,859
1,027,383
1,433,174
1,523,541
638,378

This is what the extrapolation has for PS3 the next five weeks:

619,181
683,600
883,209
943,300
577,420

These would be the 360 over PS3 sales gap for the next five weeks:

265,677
343,783
549,965
580,241
60,958

I don't think the gaps will be quite that high but I do think they will be high enough for 360 to beat the PS3 sales in 2011. You can cut those gaps down by 44% and the 360 would still beat the PS3. 

Numbers for USA and UK for December 3rd week (the two regions the 360 has a healthy lead) are up, the 360 has sold about 500k and the PS3 250k, for the gap to be the 265 k youre talking about th PS3 would have to be outsold on the rest of the world by 10k wich will never happen. Most likely PS3 will have at least a 150k lead on the rest of the world and the gap will be around 100k for the 360.

Imo they will end close but the PS3 will have the lead, time will tell if you "extrapolated" your extrapolations or not.

Numbers MS Needs To At Least Tie The PS3 For 2011:

Keep in mind that for the weekly numbers I am not counting the last week of Dec, as the PS3 will most likely outsell the 360 like it did in '07, '09, and '10.  This is due to American sales declining quite a bit after Christmas.  So I will treat the last week as a tie.

As of week ending Oct 22nd - 7,911,163(PS3) - 6,606,293(360) = 1,304,870

As of week ending Oct 29th - 8,778,992(PS3) - 7,242,745(360) = 1,536,247 or ~192K over the PS3 for the next 8 weeks

As of week ending Nov 5th - 9,129,484(PS3) - 7,520,482(360) = 1,609,022 or ~230K over the PS3 for the next 7 weeks

As of week ending Nov 12th - 9,519,074(PS3) - 8,025,387(360) = 1,493,687 or ~249K over the PS3 for the next 6 weeks

As of week ending Nov 19th - 9,878,175(PS3) - 8,441,031(360) = 1,437,144 or ~287K over the PS3 for the next 5 weeks

As of week ending Nov 26th - 10,685,643(PS3) - 9,688,395(360) = 997,248 or ~249K over the PS3 for the next 4 weeks

As of week ending Dec 3rd - ?

As of week ending Dec 10th - ?

As of week ending Dec 17th - ?

As of week ending Dec 24th - ?

As of week ending Dec 31st - ?