Called shot for something like "I want to cut the rope the bad guy's holding, so he can't drop the cage full of puppies into the gator pit"? Sure, I'm all for it.
Called shot for "I want to do more damage by hitting a vital spot"? Not in D&D, or any other abstract wound system. I kind of assume that trying to hit a vital area is an implicit part of combat.
This.
Called shots of the body part variety only seem to work, in my opinion, if the system is built around body parts.