Source, as I stated in my post, we saw 180m consoles sold last gen THUS FAR. The PS2 continues to sell about 40k a month in Japan, 250k in the US, and most likely, another 250k in other countries around the world, if not more. Therefore, it's still selling around 500-600k a month, and will slowly taper off. It could sell another 10m this year, giving last gen 190m+ as the PS2 should sell into 2008 (albiet very slowly, 300k or less/mo).
If the Wii really is selling to a new market, then the total # of overall systems WILL increase merely based on that fact. From the PS1 to PS2 generation, we saw a slight 15% increase in total console sales. I believe this # is due to the improvement of European and emerging nation sales. We could see another 15% this cycle, or even 20% from emerging nations. However, the Wii will most likely open up people to the fold, and could improve the marketshare another 5-10% of units due to this.
Because of it, I assume the Wii will get the 22m the GC got, plus another 5-15m from return users/current market purchasers, the 15% increase from last generation (about 3m units) and 5-10% of the total market growth from ultra-new users primarily in Japan. (5-10% would translate anywhere from 10-20m or more).
Microsoft will EASILY, and I mean EASILY beat out the first Xbox by leaps and bounds. The 360 has to sell just 3m more units w/w between now and December to truely overtake the Xbox in a time-and-date way (assuming MS pulled the plug 4yrs into sales). Of course they won't, so I'd expect 15-20% more sales for each year that MS keeps the system alive vs. the Xbox. The Xbox, had it of had a lifespan similar to the PS2 (or atleast 6yrs), could of sold 30m units or even 32.5m before ending had MS kept it. The Xbox 360 should, at a minimum, do 30.0-32.5m. However, with no true American successor to the PS2, improved emerging markets, and decent European gains (remember, it's already sold 3m of the 8m that Europe sold for Xboxs, before any price drop, no Halo), we should see sales of 40m or more. I'd put 40m as a minimum for the 360, and could see upwards of 55m if the European situation really improved, and the pricedrop really really helped sales (increased sales #s by 30-40%).
Obviously the PS3 has the most to lose, as it won't really get a benefit from emerging market sales, as they can't afford the PS3 en-masse until maybe 2010 or 2011. It won't see the growth that the Wii or Xbox will see.
The most important question is: how will emerging countries like China, India, eastern Europe, South Korea, Austrailia, and non-UK west European countries vote on video games?
A few ideas per region:
Japan should see a dramatic increase in hardware sales due to the Wii. I expect sales of 45m consoles between now and 2012 (24m Wii, 15-16m PS3, 3m X360).
America should see a typical increase to around 90-100m consoles (37.5m X360, 30m PS3, 22.5 Wii, between those numbers and 5% more for each console)
Europe should see the greatest increase as they become more tolerant of video games, and a greater income in eastern Europe. One of the reasons Germans can't afford games like the UK can is because they're still recovering from the re-joining of East and West, and median incomes aren't very high for around 30m of those germans. Europe, between east and west, should sell around 55m consoles + extra sales to the Mid East and Africa (25m PS3, 15.5m Wii, 15.0m X360)
Emerging/Other markets will be the major ones to look at, as various countries will adopt various systems. Austrailia should stay in Sony and MS control, South Korea will go Sony/MS due to online, China will go Wii somewhat, India will be up in the air, and the other various countries will minorly pick between the 3. We should see sales of around 5-10m for each console by the time everything's said and done. Austrailia should provide atleast 2.5m consoles total, with SK, China, India, Taiwan and the Phillipines doing similar numbers, and the other ones (South America, ect) providing 0.5m to 2.0m units per country....Nothing major that'll show up on any press release except for "we shipped X # of systems this quarter).
So I think we should see around 200m consoles sold just between Europe, the US and Japan. The rest should/would be from Emerging markets for around 10m to even 30m units sold if China and India start buying video games on some sort of meaningful level...If not more.