They simply can't afford too big a gap with the competition, so they have to be ready for a price drop sooner rather than later. And I think they aren't happy with not selling at their full production capacity either. And I'm quite certain that they'll not sell enough consoles, even during Christmas, at $600.
This obviously despite the fact that content is also an important factor. I know that here in Europe, regardless of its price, the console will start selling as soon as those soccer games hit, and even at this price I can see a lot of people getting one for Christmas. Once it grabs people's attention with good content, then they will be motivated enough to figure out that in terms of value for money and actual cost, the PS3's price isn't that bad. But even here they can't afford to let the gap become too wide, and in other regions, they will have to fight harder, against Nintendo in Japan, and Microsoft in the U.S.
But if they can, I think they'll more comfortably sit in a position where they can make more than they can sell, and if they can achieve that with the consoles selling at a break-even point or even a fraction below, I'm sure they will go for it. They don't just have themselves to consider, but also game development budgets. If sales for PS3 software take too long to get going, they may lose more third party support than they should be comfortable with.
So all in all, yes, I agree with Shifty that a price-drop is certainly possible. I don't expect it before september, but it is possible we may see two smaller price-drops, the first in order to get old stock out, and the second upon introducing the one that is cheaper to produce.