D&D and new age in the same sentence is purty darn funny. I'm not even going to bother arguing about D&D because most people are SO missinformed it's sad.
undeath (whatever that means),
I don't know if you have a typo or not but I do believe it should say undead. Undead refers to things (not real of course) such as "zombies", "ghosts", or any other sort of "undead" fictional creature. Things that are "undead" just means they don't breathe, or "live" and they haven't stayed "dead". It's a pretty funny term indeed but they had to give it some sort of title.
I know of NO ONE that worships anything from fantasy books. That doesn't mean there aren't retards that do, but I personally know of none.