Found this quote on Ars Technica: "While it's simple for end users to re-flash their hard drives using executable files provided by manufacturers, it's just about impossible for an outsider to reverse engineer a hard drive, read the existing firmware, and create malicious versions."
This would have been funny if it wasn't so tragic that they believed this. I posted this in another comment:
http://spritesmods.com/?art=hddhackSo much for "just about impossible"