The Inq heard from one of IBM's Semiconductor VPs that the yields of the cell processors which are used in the PlayStation 3 are in the 10-20 percent range.
With logic redundancy (translation: 'PS3 buyers only need seven SPEs [Synergistic Processing Elements], more would just be too much for such simple creatures'), they can double that. This suggests yields of 20-40 per cent.
Intel would have a hit squad sent off to deal with production execs if one merely cracked a joke about 70 per cent yields, and I can't see how 40 per cent will ever make the PS3 economically viable.
Once this gets out, look for a triumphant Sony exec to tell us about how it may be slow and de-featured, but the PS3 will be reassuringly expensive, and profits are for lesser companies. Besides, we mere mortals just don't get what Sony is trying to gift us with, DRM infected lock in.