Rotating media.
@Eddie Edwards.
This is indeed true what you say. But it's only this cheap because of massive volume sales. I'm sorry for my earlier generalisation, but it's only a matter of time. My prediction was based on another couple of years before the world's economy is back where it was a couple of years ago.
By this time, SSDs will make today's look stupid at the current rate.
Silicon doesn't have to reach the cost of rotating media at all. It only has to reach a price where large numbers of people are tempted for a big enough disk. Once large numbers start buying, this eats into the profits of the rotating disk drive manufacturers, causing price rises. It also encourages investment in future tech,
A could buy a terabyte 3.5in for whatever, say 100 quid, but I'd much prefer a state of the art 250Gig SSD for four times that much. Most ordinary people don't come close to filling a 100Gbyte drive. It's performance they would prefer (were they not blinded by the marketing hype.)
As more and more people see their mate's ludicrously fast SSD based laptop, they'll want one, and while I agree that it's not all roses at the moment, technology solves all, and we have to bear in mind they've only really been mainstream for two years. They're getting better almost every week.
I don't deny that there will still be people with super large data requirements, say >1 PByte that will still use rotating for longer, but everyone else won't. In the end, rotating drives will have the same customer base as mainframes, such as government and research companies. The long tail of small purchases will, once it starts, disappear quite quickly I think.