The flooding in Thailand has caused severe supply disruptions for hard disk drives. See Memory and Hard Drive Prices: Win Some, Lose Some as well as the previous OWC Comments on the Hard Drive Availability Situation.
The latest (opinion) from Larry O'Conner at Other World Computing (OWC); OWC sells a lot of hard drives and external drives which use hard drives, as well as their solid state drive offerings.
Supply has eased a little bit, but still ugly for next few weeks - but we've gotten some allocations with better costs than we had to pay in November and that's helping. I personally believe we'll see normality by July and that end of the year is wishful profit thinking on the HD makers part.
WD is short about 60 mil drives... But they have the highest capacity once back online and they are coming back online quicker than expected. Seagate and Hitachi have added combined about 15-18 mil drives to their Q1 production plans... I think by mid-Summer will be a lot better... And definitely bigger improvements by April.
Lower capacity notebook drives are scant to be found at all right now FWIW though. Note - all my opinion on future.. Could be longer or shorter... Currently industry experts believe 12-15 months recovery.
Trends I see suggest another 5-7 months to be back to normal output and likely a lot higher than pre-flood till catch up. But up to the big three in terms of impact to the price side of equation. Supply will determine though and sure seems like supply will be back by mid-Summer to pre-flood.