Yikes, read this post on a Microsoft forum and it has scared me a little bit about Vista's BitLocker feature.

http://windowshelp.microsoft.com/communities/newsgroups/en-us/default.mspx?dg=microsoft.public.windows.vista.security&tid=9550eb1d-edd7-4905-8e8a-fcaa997faa99&lang=en&cr=US&sloc=en-us&p=1

This essentially means that your system "may" have a significant failure because of a single bit error on a drive.  Now I know I'm sounding a little brazen here, but this is a legitimate concern for users, especially corporate users - the ones most likely to implement this feature.

The only workarounds to this problem are:

1. Don't use BitLocker - Less security is safer?
2. Perform regular backups of your system - this may help but a typical user won't be capable of restoring their system without administrative intervention.  So you end up taking a user down for a day to get their system restored or rebuilt from image - great, just great.

I guess we'll just have to wait for a RAID-able solution.  or some type of parity option.