After reading a lot of forum posts about FileVault 2, almost everything seems to be clear to me, but I still have one important question:
My Macbook Pro (on Mountain Lion) backups automatically to my Time Capsule through Time Machine. When I enable FileVault 2, and my Macbook is stolen, can I just buy a new Macbook and restore it from the (unencrypted) Time Machine backup? Or will this give problems because the 'original' Macbook the backup was made off, had FileVault enabled?
To answer your question directly, yes, you would be able to purchase a new MacBook and restore from the unencrypted backup. The backup data is not encrypted by default, that is why you can only back up to Time Machine while logged in.
You can also choose to encrypt your Time Machine backup, in which case you would still be able to do the same thing, it would just require you to enter your Time Machine's password to start the recovery process.