So, what can we take away from this? Sometimes things come as a surprise. I say quit asking Pete questions and just wait till the game comes out so he doesn't spoil EVERYTHING.
How is this a spoiler? It's basic game mechanics, so there is a perk to decapitate people? Fine, when will we hear about the remaining perks? Any "normal" developer would have revealed such stuff long ago, to draw interest to their game, and would've kept the fact that the player is the Dragonborn secret.
As for the Perk, IMO it's a waste of a perk-slot, just like bloddy mess in Fallout was a waste of a trait. Won't pick that one unless it has other benefits or there are no other useful perks left.
I have no problem with gory deads per se, but I'd prefer them as game setting, consequence of locational damage or weapon ability.