I believe with the hardware manufacturing costs slowly dropping, and improved yields for the CELL and RSX, and the fact they are earning more on software sales now is the reason why the PS3 will be able to pull itself a profit. I also believe that due to the new video store and increases in PSN purchases they are pulling in even more money from that.
The PS3 wont be profitable yet on the hardware but I think the software is what will save it. Also I think as Blu-ray increases in sales, the rest of Sony wont wince as much if Sony did cut the price a touch.
Still the switch from a 40GB HDD to an 80GB HDD actually boosts manufacturing costs by $10 - 15 so the can just stick with the upgrade for a bit.