I would like to know if any NPCs were capable of decapitation prior to DG. I have seen these vampires decapitate several NPCs. And I just suffered my own decapitation a little while ago. I have been eaten by dragons, launched into space by giants, and generally beaten up by all manner of enemies before. But this was the first time my head went rolling. (Gave me a chuckle, actually. I was getting a little cocky and needed to be reminded I could still get killed.)

This was possible before Dawnguard because I remember countless many times where I saved right before being decapitated by a Bandit Chief.

Yes, I had the misfortune to have to sit through my own killcam decapitation...

At least that's better than getting the dragon killcam from its' tail end, only to find out you were the one being killed.

If I used other people's quotes in my .sig, this is the one I'd pick!

It was there prior to Dawnguard.
I remember taking Umana's head off in Alftand Cathedral shortly after Skyrim came out.