Hi Bruce,
Like Doug mentioned, it is a personal preference as to whether you should add anything to the pulled pork. I typically will put together a sauce with apple vinegar, tomato paste, rub and anything else I feel like adding. The vinegar tends to cut the fat in the pork. I always heat the sauce up before applying it. I try and not put too much on since the taste of the pork is what I am after.
I've been served pull pork sandwiches before that were drowning in a tomato based sauce. I couldn't taste the meat.
-mc