So I have good news and bad news. The good news is that if this is an original FileVault bundle (and not the newer FileVault 2, which is much more difficult [if not impossible with a strong password] to break), there is a chance it can be recovered. The bad news is that it still requires cracking 1024-bit RSA which is no small task, or 3DES which might be slightly easier.
I have even better news though. A group of security researchers released a tool to decrypt FileVault and FileVault 2 encrypted disks. Let me preface this with an obligatory statement that we do not condone using this utility on data you do not own but, assuming it is your data, you can find the utility here: https://code.google.com/p/vilefault/
I can't make any claims for its effectiveness but it's certainly worth a shot. Good luck!
Edit: And yes, this is a commission. I'll move it now.
I have even better news though. A group of security researchers released a tool to decrypt FileVault and FileVault 2 encrypted disks. Let me preface this with an obligatory statement that we do not condone using this utility on data you do not own but, assuming it is your data, you can find the utility here: https://code.google.com/p/vilefault/
I can't make any claims for its effectiveness but it's certainly worth a shot. Good luck!
Edit: And yes, this is a commission. I'll move it now.