It's trivial cryptographically, but from a security point of view, it's not necessarily trivial at all.
If we assume the courts can order you to decrypt the drive (and without debating that point) - one has to consider that the court may be fully aware that the system has multiple hidden volumes, either by eyewitness testimony, 3rd party evidence (check out truecrypt's warnings on their site about full system encryption and what to watch out for.
Things like finding the same windows installation doing every update twice. There are all kinds of information leaks that COULD pop up.
I'm not saying it's impossible - just as strong cryptography, which is easy and is all over, doesn't mean all our data is secure, neither would a more complex system like this protect someone from the legal system.
If we assume the courts can order you to decrypt the drive (and without debating that point) - one has to consider that the court may be fully aware that the system has multiple hidden volumes, either by eyewitness testimony, 3rd party evidence (check out truecrypt's warnings on their site about full system encryption and what to watch out for. Things like finding the same windows installation doing every update twice. There are all kinds of information leaks that COULD pop up.
I'm not saying it's impossible - just as strong cryptography, which is easy and is all over, doesn't mean all our data is secure, neither would a more complex system like this protect someone from the legal system.