I have just installed the Windows 8 Assessment and Deployment Kit and came across some information about Windows 8 support for eDrive also known as the Encrypted Hard Disk Drive..
The Windows Setup Reference mentions a new setting called Microsoft-Windows-EnhancedStorage-Adm / TCGSecurityActivationDisabled. By default, when Windows is installed on an eDrive, Windows automatically encrypts the drive by using TCG and IEEE 1667 transport standards.
eDrive Device Guide
Almost All Future Drives Will Self Encrypt, Says Tom Coughlin, in Industry’s First Forecast on SEDs
Building hardware-accelerated encrypted devices (eDrives) in Windows 8