thinking further..
This would also add to another level of the raise dead spell.
so let's say raise dead is level 6 spell? then the next raise dead level spell would be
called "Regenerative Raise Dead"
so.... ?...
A player kills you but walks away leaving your corpse undefiled? no problem. You use raise dead spell.
A player kills you and does defile your body? By taking a body part from you?.. You use Regenerative Raise Dead
Spell.
A small message appears as your body rises to the land of the living once more. "Although your body has been defiled.. the energies have recovered your "Enter here/Claws, Head, Organ, whatever" once more so you may rise once again!"
It would need to be shorter. Maybe? "You regenerate to live again" which would mean.. you had been cut apart for components but the magic of the gods/of the realm has reformed those missing parts so you may continue on.
Or.. If raise dead spell or enhanced raise dead spell are not going to ever be viable mechanics then make it so it takes longer to 'get up again' after dying with a small message attached as you raise to your feet. Mind you there is also risk because the player taking the body parts off of you will need to spend that extra time on your body doing the deed which will also make him more vulnerable to attack so there is an upside and downside to it all.
I personally think this is a great idea. PvP has so few rewards in it as it is.