this is a tricky discussion: The Brittish police wants Microsoft o create a backdoor in the new encryption feature in Vista that will let you encrypt the whole disk: OS included. The police are afraid that this feature will give them a disadvantage in the fight against terrorism.
This backdoor wil (afaik) also weaken the feature: why use something where you know there is a back door to it. It renders the encryption worthless.
I know there are also arguments in favour of doing this and there are different stories going around about this backdoor feature existing in all encryption mechanisms, but saying so out loud renders the feature worthless for serious applications.
this is just my first thought about this issue, and there are much more sides to it than mentioned here, but fromo a security perspective I would not recommend this feature being backdoored.