A couple things they don't take into account:
1. Nintendo has made an extremely healthy profit on every single console
2. Sony has taken considerable loss on every console sold, and are still not profitable yet
I don't know if PS3 will sell over 125 million consoles or not. Even though the blue-ray drive is said to be the next-gen video storage standard, it is still not widely used. The DVD is still, by far, the most widely used standard for movie rentals.
By the time that Blueray surpasses DVD (which I am not sure is going to happen anytime soon with the popularity of $1 rentals at redbox, and the extra expense of Blueray), Blueray could be obsolete itself. Video streaming is the new technology and it is widely adaptable. With companies like Netflix, Blockbuster, and Walmart jumping into video streaming I am not sure how bright the future for Blueray is. It may never supplant the DVD in the way that the DVD supplanted VHS.
Let's be honest here: a lot of people bought PS2s to use as DVD players, and a lot of people bought PS3s to use as Blueray players. This demographic might have bought a game or 2, but not much else. PS2s also had a significant jump in sales because of the high system failure rate of the PS2-- people had to buy more than 1 PS2.
Once Sony drops the PS3 price down to $200 (in the next 2-4 years), there may be a few people that are interested in picking the PS3 up as a Blueray player. However, if Bluerays have still not achieved critical mass in society-- then less people are likely to buy the PS3 to use as a blueray player.
There are a lot of factors that need to be considered in this analysis. It is still not at all guaranteed that the PS3 will be able to have the longevity that the PS2 did.
I think the PS3 should be able to sell 100 million units, but can we really expect the sales of PS3s to continue growing every-year in a cyclical console business? I think the PS3 will hit a peak in the next 2-4 years. If Xbox and Nintendo release new consoles, this will also limit the growth ability of the PS3.
The PS3 can only sell over 100 million if maintains growth for the next 5 years. I'm not sure it can do that.
Most anticipated games of 2011:
Uncharted 3,Legend of Zelda: Skyward Sword, Rocksmith
Modern Warfare 3, Super Mario 3D