OK, I've been working on this issue for two days now and managed to make a little headway. I have a Windows 7 machine that is full disk encrypted via truecrypt, with preboot authentication enabled and NO rescue disk of course! The other day, the machine just stopped booting (blinking cursor). After hanging it as a slave on my Linux box I was getting nowhere trying to mount it (Invalid Password or Not a Volume). Today, I found some recommendations on Mounting via the Windows version of TrueCrypt, Specifically Mount Options -> Use Backup Header & Without Preboot Authentication. I can't decrypt the drive using Truecrypt because I believe the Primary Header information is damaged and it gives me the Invalid Password error. Nor can I backup or restore the headers because of the same issue. I tried to get testdisk to analyze the partition, It will not recognize that windows has mounted the partition as a 3rd drive letter (C: Local Boot Drive, D: Encrypted Drive Innaccessible, E: Encrypted Drive Access to encrypted files) I was able to recover the files, but I'm not sure if it is actually possible to batch decrypt them.
You got lucky in a sense. Now make a rescue disk TODAY and keep it for the time you don't get lucky!!