Well according to this graph, the PS3 has sold more, is selling more, and will sell more than the 360. No one seems to remember the 12 month headstart the 360 had, and better yet, it had it with no competition, which really shows how awful its sales are that it had an entire year on the market by itself, and PS3 and Wii are selling better.

why does it even matter?

WHY gap in October-December 2007 increased in favour of x360, when:

VGChartz Hardware data for the period 06th Oct 2007 to 29th Dec 2007:

It sold more in November and less in December.

It still wrong, it should increased in September by a lot, and not so much in October.

VGChartz Hardware data for the period 08th Sep 2007 to 29th Sep 2007:

VGChartz Hardware data for the period 06th Oct 2007 to 27th Oct 2007:

I think the real question is one of accelerating or decelerating trends in various markets. To that end plots of the derivatives of your graphs --maybe with a 4 week moving average to smooth out spikes-- might be more insightful. Your choice of scaling factor makes it difficult to make out changes in tangents.

Please don't take this as criticism of your hard work though.

Japan: Done deal, has been en will stay that way. Even now when the 360 has more rpg's out PS3 is leading the way. Never mind when de rpg start coming to the PS3, games like eternal sonata, White Knight, Final Fantasy, Final Fantasy VS and others are coming to the PS3 back to back. Along whit games like Africa and LBP I expect the PS3 to gain momentum finally.

America: Will remain 360 territory. However Gears2 will give it a final push above the PS3, after that I'll see difference between the two slimming down bit by bit. The graphs already show that the difference is slowly changing to the advantage of the PS3 and I expect it to go on this way.

Others: This is the real warzone this generation and it's going towards the PS3. I just have to look around towards my and my friends, 1.5 year a go some had a 360 now a days everybody is getting or already has a PS3. Unique games like LBP, the different shooters and rpg's coming will further increase this trent. The PS3 is gaining more and more momentum and I expect that during the holiday season it will explode.

WW: It will take some time but eventually the PS3 is gone overtake the 360. It won' t be before the end of next year however.

Also, to the people who think there will be a new xbox arriving soon, there are no symmetric core chips on anyones roadmaps that I know of (please enlighten me if I am incorrect) which will give the same compute "power" increase as even the 360 had to the original xbox which has been a bit of stretch to sell to consumers.

They could go with more esoteric architectures, however they are going to be running into the same problems with immature compilers and game developers who have become to cozy with the x86 paradigm that Sony had. And they won't be able to rush development, like this time.

Cell is almost there with raytracing (my raytracer is now getting 13 fps at 480p on cell), and cell+ is probably best placed to pull off the holy grail. Since Sony divested their all cell assets (correct?) MS could jump on cell+, but one wonders if their wouldn't be a revolt in their developer community as their whole raison d'être in language development since their humble beginings as been a Hilbert program like "higher and higher levels of abstraction". Abandoning the current state ideology of "dialectical linguistics" I think will be tough for them to swallow. This is not just a MS thing Umberto Ecco wrote a facinating history on the history of the obsession of finding the perfect language -- as mocked in gullivers travels -- among Western acedemicians dating back over a thousand years.

Now I am officially way off topic, so I end here.

This time next year PS3 will be well ahead of X360 and the graphs will look a lot different.

The other interesting trend would be Wii vs PS3+X360