Considering technology advancement in semiconductor and the economy, I suspect one to come around next spring.
IBM and Toshiba has both announced that their fabrication plants are ready to manufacture 45nm versions of the Cell. TSMC are also ready to do the same for GPUs. This should be one of the main push that will bring the chip cost down.
Blu Ray drives are getting increasingly cheaper, so the Blu Ray diodes are also going down. Considering the PS3 uses a slower 2X blu ray drive, production yield for them should have improved dramatically.
Add these along with the basic learning curve model for production, the basic production cost of any product is reduced by 10% for every doubling of the cumulative production.
Finally, the economy and disproportion of the yen to the dollar is getting better. You never want to make them using expensive parts and then sell them to cheap dollars. When the economy stablizes by mid-next year, a price drop can be put to much better use.
