I dont think anyone can be sure which console will sell how many units by the end of its life, the analysts look at previous generations and use that as well as other factors to guess whats going to happen. Most of these same people didnt expect the wii to sell like it has so far, so i dont think anyone can guess the next 3-5 years of console sales.
I guess the reason behind them forcasting the PS3 sales as so high is from previous gens and the fact that it has done as well as the 360 did in its first year without its "big" games, at a much higher price point with more competetion. By the end of the year the PS3 will of sold approx 8 million consoles, not to bad for a console with no games is it? I dont think in the end it will be PS2 sales but then again i dont think the wii will be either, in the end i expect the wii to have good sales everywhere, xbox360 to dominate the US and the PS3 to be a close second in Japan and EU/ROTW.
To the comments about the shares of Sony, well even in this so called bad year for Sony share prices are now $15 more than a year go ( 41-56) if i was a Sony share holder id be pretty happy, Microsofts in comparrison have gone up about $3, Ninetendos have gone through the roof!!
As for PS3 sales exploding well since the price drop the PS3 is now selling more consoles a week than it was a month earlier in the year in both the US and EU, and in Japan the PS3 sales have gone from 9-15K a week to 35-55K a week so although not an explosion its a big increase. Some of which is down to holiday sales but its momentum started in october, way before the holiday sales, next year when the more anticpated games are out it will get another sales bost, but still cant see it as big of boost as the forecast.