So far this year, the ps3 has sold ~5.6 million units globally, while the 360 has only sold ~4.0 million units.  The ps3 has sold roughly 40% more than the 360 so far this year:

http://vgchartz.com/hwtable.php?cons[]=PS3&cons[]=X360®[]=Total&start=39453&end=39649

The 360 has sold ~4.0 million units this year compared to just ~2.5 million units in the same time frame last year:

http://vgchartz.com/hwtable.php?cons[]=X360®[]=Total&start=39089&end=39278

That's roughly a 60% increase in sales year over year.

Now assuming that it has a similar increase over the holiday season (I'll use the beginning of November to the end of December in this case...), then the 360's holiday sales for this year would probably be around 5.4 million, compared to just 3.4 million last year:

http://vgchartz.com/hwtable.php?cons[]=X360®[]=Total&start=39390&end=39453

Of course, that is a highly unlikely scenario, given the fact that the 360 had a very slow start to last year, and very big finish due to Halo 3 + price drop, leading me to believe that the 360 won't have the same percentage increase during the end of the year as it has had during the beginning.

Anywho, assuming the ps3 stays a consistent 40% above the ps3 for the remainder of the year, than this would imply that the ps3 will sell around 7.56 million units over the holidays, thus shaving off ~2 million from the 360s lead.

Of course, it's not likely that the ps3 WILL sell 7.5 million over Nov-Dec, much like it's not probable that the 360 will sell 5.4.

However, it IS probable that the 360 could sell ~4 million units this year, with the ps3 selling ~5.6 million units, still shaving off a whole ~1.6 million in just two months.

In the end, I believe that the ps3 WILL pass up the 360 in 2009. It will happen no later than the end of the year, and could happen earlier, depending on when GT5 releases and when FFXIII hits in Japan. I had originally estimated that the ps3 would surpass the 360 around the middle of '09, but now that it seems GT5 and FFXIII probably won't release until very late '09 or even 2010, so it's a bit unlikely to happen that early. But it could, no doubt about it.

if they change their strategy they will do.

Think it will surpass late 2009.

Maybe with a price cut around October and some aggressive marketing.

Guys, between the HD systems...regardless of who ends up in 2nd or 3rd, since almost all 3rd party titles aren´t true exclusives, then that # 2 spot really doesn´t matter much, save for bragging rights....agre/disagree?

I know I say that very often..... Not true

It's definitely possible.  Assigning any reasonably accuracy likelyhood is impossible because we do not know Microsoft's strategies or Sony's strategies.

Personally, I think Sony has a very good chance to surpass the 360 sometime between October 2009 and December 2010.  At that point we will be about one year from entering the next generation with both the PS4 and next Xbox almost certain to be out by 2011 or 2012 at the latest.

 Im so confused. Are you asking me to be more specific than Q3 next year? Me no understand

Ok, here's a question: When (specifically which week) did the PS3 first outsell the 360 on a worldwide basis? Wasn't it in November or December of 07 at some point? Point is this: Go to that date and compare sales to date of both consoles (in total) and then divide by the number of weeks.

The last I checked (after MGS4 data were in), The PS3 was outselling the 360 by about 50K/week, on average, worldwide. Take the total spread and divide by 50K and you get the number of weeks remaining. The one big assumption is how big that spread will be over the holidays. Will it be 2X the weekly average? 3X? 4X? Even at 4X the average, we are talking 200K/week (!) times 8 weeks for Nov/Dec which cuts the lead by 1.6 million WW over the holidays. Figure that still leaves us with a delta of 3.8 million (5.4 million (today's number) minus 1.6 million this holiday). Divide 3.8M/50K and you get 76 weeks or about a year and a half. That would mean holidays 2K9 assuming the 4X multiplier pans out THIS holiday.

Why do these people assume the ps3 will even outsell the xbox360 over the holidays? 3 or 4x! Thats just crazy! There might be ps3 exclusives but xbox360 will have them too. 4x xbox 360 would put ps3 over wii sales. I DON'T THINK SO!!!