I'm currently preparing a Bitlocker screencast for your viewing pleasure and recently noticed one of the side effects of applying Bitlocker on your drive. Well it's not really a side-effect it's just proof that it works!
I was running another build on a different partition (as you do) and tried to access the disk that I had bitlockered - and lo and behold - I couldn't gain access!
In the screencast, I'm going to try and analyse the data on the disk using some forensic tools which will prove that you can't read what's on there - even using proven data extraction techniques - Stay Tuned!
Here's the screenshot of the message you get: