Well, the term refers to Jewish magic and the idea that some energies or beings are polluted spiritually, concealed from god, corrupted, or confused.
In D&D terms, I think that there shouldn't be much of a difference between them and Abyssal creatures, if you go with the idea that the Abyss is what was left over of the primal energy after the gods made the universe. Demons are created by the Abyss to bring creation back into its fold. Maybe Qlippothic creatures in Pathfinder are Abyss spawned beings that the Abyss managed to spawn directly into the Prime Material.
I think this is the interpretation I'm going to use for my game, sense the party has been growing in their power and are getting ready to take on Shuma Gorath when they return to their home world. I think the Elder Gods like Shuma Gorath, in Pathfinder world, were Abyss spawned deities in the prime material that observed the creation of the universe by the hands of more rational beings.
Personally, I think for a template you should use the Demonic template as a base, with SR and Fear coming on at pretty low hit dice. I'm not an expert on the rules and tend to make up stats directly for each creature as I write them, but I wouldn't think there is much reason for them to be different than Abyssal creatures.
