Sony could be looking to lose that much money if the company views it as an investment.
Here is what I mean.
Microsoft and the Xbox. Microsoft lost alot of money on the Xbox and Xbox live setup. However, that 4 year investment looks like its about to payoff with Xbox 360. Microsoft now has name recognition in the industry, and are launch a new system perhaps 6 months to a year before the competition. This can be a big head start for them, and could help them capture huge marketshare.
With that comes new means of making a profit:
More expensive memory cards, Controllers, Games, selling special online content, ect. ect.
Now Microsoft would not be in the position right now to make the money they are without the intial investment with Xbox.
Sony is looking at the big picture too. Sony is trying to launch and win a new format war with Blue-Ray Video. But as of right now a straight out battle would be hard for them to win on just releasing the player.
However, package it as a part of the hottest video game system around the world, and perhaps you can make back you investment.
So Sony:
Buys another movie studio company to give them larger collection of movies
Releases the PS3 at an acceptable loss to bring in consumers
Sony will make its money off of:
More expensive games, more expensive Blu-Ray DVDs, probably more expensive controllers and memory cards.
It's not a bad strategy if it works. Sony's strategy is like Microsofts, but with an added profit maker in the movies.
Sony is using the same strategy for the PSP, and you know those PSP movies are going ot make them money if they catch on.