What I don't understand is that in a context of a court (and this group of competent professionals), password disclosure _should_ be considered self-incrimination (although there was at least one case in the UK where a judge came up with some loophole reasoning around that). Disclosure of multiple passwords ("we didn't like what we found, do you have any other passwords?") would certainly be obtained under great duress.

To make sure that you can't distinguish free space from encrypted noise, you have to write random noise everywhere as part of the filesystem creation process.

The one thing Truecrypt is vulnerable to is that you can note what parts changed -- say they raid your house twice and image it between when you used it. Then they'll know that free space isn't really free.