Sony has put itself in quite a pickle here. If they don't radically change thier price levels they will have to stop production soon. That's not exactly cheap and would leave them unable to deal with any unexpected surge in demand later. We can look at how much they lose on each sale but that's not how most businesses operate. At least not when it comes to annual sales and profits, longer term is a little different since production can be sold next year and such. They are paying to make a set number of PS3's whether anyone buys them or not. Apparently they plan to make around 10 million PS3's this year which would cost between $6.5 and $7.5 billion. Assuming software sales of 5 games per console, 3 million consoles sold before the year, and $15 profit for each game (I'm probably off on that but I doubt it will change things much) then $225 million in software profit will already happen. That is the fundamental start point for any calculation of Sony's losses.
The next question is what would happen to the PS3's sales with price cuts. The PS3 is riding at the $600 saturation point with its 200k a month in sales. The 360 is riding at the $400 saturation point in NA and near it in EU with ~350k a month in sales. Adjust for the WW $400 point and compare to the $600 point and Sony could at best expect to pick up 100k per non-holiday month in hardware sales at $500. Let's say Sony goes crazy and cuts $200, I would guess the PS3 at $400 could sell about 500k per non-holiday month.
Given expected sales a general profit picture can be constructed (I know revenue is a little high since Sony doesn't sell the PS3 to stores for full price, but it'll work as an example). At $600 they are trending towards about 3-4 million in sales this year. Assuming a similar software sales environment that would equate to $2.6 billion in revenue and losses of $3.9-4.9 billion (or over $1,250 per console sold). With a $100 price cut the PS3 could sell 5-6 million. That would lead to revenue of about $3.4 billion and losses of $3.1-$4.1 billion ($650 per sold console). Lastly, I do think a cut to $400 would allow Sony to sell 9-10 million PS3's. In that case revenue would jump to about $4.8 billion with losses of $1.7-2.7 billion ($230 per console sold). With the $600 and $500 price Sony could lower production 5 million and save around $2.5-3 billion (I'm not sure what the exact cost of that would be). Although this would be at the price of later profits as the production line would have to be restarted at some point, especially with a $500 price cut where production would have to be quickly restarted/ramped up.
A few things stand out, most notably all of those losses are enormous. Without a price cut it is simply impossible for Sony to maintain a 10 million annual production rate for the PS3. Without a serious price cut it will probably be impossible to maintain 10 million a year next year. While shuttering production to equalize supply with low demand while keeping the price at $600 may be the best option for the bottom line this year, odds are good that doing so would cause lasting damage to the PS3. The Wii will likely end this year with an install base of around 22 million while the 360 should have at least 14 million. If the PS3 is sitting at less than 8 million it will be in serious trouble game wise and would probably never recover. Then again would cutting $100 and ending at 10 million make that much a difference? Profit-wise a $100 price cut with a temporary production lull would be best over the next 2 years. However, the only thing that could really save the PS3 long term is a $200 price cut but I doubt Sony could absorb the huge permanent losses that would entail. Sony would basically be trying to save its install base at the expense of ever being profitable. I should point out that by saying one thing is better than another here we are still talking billions in losses, just that $1.5 billion is better than $2.2 billion for example.
All I can say to Sony is greet Mr. "We can sell a console for $600" Rock to your right and Mr. "We can lose $200 per console" Hard Place to your left.