Xbox 360 v PS3
Here we have three charts representative of the three main regions as recorded by VGChartz, and a global chart which brings all of the data together. The line on each graph represents the gap in install base in millions (sales through to consumers), and the title indicats which console is in the lead in the particular region covered.
Americas

Japan

Others (Europe, Asis, Africa, Australasia)

Global

HD Consoles (360 + PS3) vs Wii
For the Wii to reach 50% market share the graph line must drop below zero

Commentary
We have a new trend almost everywhere.... the PS3 continues to make significant inroads to the 360 lead in Others and Globally.
The turnaround in Others and the sustained high sales in Japan have caused a marked difference to the Global chart. The turnaround is now looking more impressive than what the 360 managed in a similar period last year.
The Others gap chart will likely be a "PS3 Lead" chart by the end the year.
The effect is far less dramatic in the Americas and despite the recent out performance here it looks as though the 360 will certainly hang on to a very substantial lead. The holiday period in the Americas (particularly the U.S.) will be a hard fought battle.
The gap between the Wii and the HD twins increased again this month despite the Wii price drop. The substantial increased in PS3 sales being the primary reason. It seems unlikely that the Wii will achieve the 50% market share of total install base.... although a handy holiday performance can change that so easily.
November is a huge month for console sales. Black Friday is approaching and some big numbers will be posted in the U.S. as a consequence... for all three consoles.
The charts may look very different again when I report back in a few weeks time.