Getting lots of requests for information internally and externally for Longhorn's Secure StartUp and Full Volume Encryption (essentially a trusted platform module (TPM)-based security feature for data protection).  Looking forward to getting my hands on a machine with a TPM to start getting familiar with how this all works in practice.  For a decent exec overview, check out http://www.microsoft.com/whdc/system/platform/pcdesign/secure-start_exec.mspx.  For a better tech overview, check out http://www.microsoft.com/whdc/system/platform/pcdesign/secure-start_tech.mspx.

For more info on TPMs (including a decent list of hardware vendors who currently offer them), check out https://www.trustedcomputinggroup.org/home.