Can Macbook be serviced by Apple Care with FileVault enabled? A few years back I had to send a Powerbook to Apple for hardware repairs (the optical disc stopped working and had to be replaced.)

I had FileVault enabled, and the tech at the time told me I'd have to disable that encryption in order for them to implement the repairs. So for privacy I just re-formatted the entire OS (having a backup, of course) before handing it off.

Is it still the case that Apple requires FileVault(2) to be turned off before they will repair a Macbook?
Firstly, I think this would be better handled by calling Apple Support directly. I do not see mention of this in any of the repair terms and conditions documents on apple.com.

Secondly, regardless of whether Apple requires FileVault 2 to be disabled or not, I would recommend that you follow the same process you did before - backup all the data, reformat it and install OS X afresh before giving it for repair. This would protect your privacy and also reduce (or prevent) wasting time with support if/when they inform you that they would have to format the drive and install OS X because it's encrypted with File Vault 2.