WD уменьшает гарантию на некоторые модели винчестеров до 2 лет (практически на все, кроме enterprise версий):
This new warranty policy will be effective for drives shipped from January 2nd, 2012. It is important that you take a moment to update your website(s) and collateral to reflect this change for effected drives shipped after January 1st, 2012.
All drives shipped to distributors prior to Jan. 2nd 2012 will retain the current warranty terms. Because of existing inventory in the distribution channel there will be a short period of time when some drives with a 3-year warranty will be sold at the same time as drives with a 2-year warranty.
If you have any doubt about the warranty of a drive you purchased, you can go to support.wdc.com, select Warranty and RMA Services and proceed to the Warranty Check page.
У Seagate всё в порядке.