I think Jacob's Nemesis has been using dead people for longer than we all think! Is it possible (i think so) that the Nemesis used Christian Shephard dead body when it crashed landed on the island in Season 1. I also think that the Nemesis used Claire to break the ash line which surrounds the hut so he could escape and finally kill Jacob.
I have additional evidence to back this up: Firstly, it was Christian who told Locke to get the Oceanic 6 back and he told him he would have to die to do it. Was this part of the Nemesis plan to finally use a body (John Locke's) to get close enough to Jacob? Secondly, since Locke's reincarnation we have not seen Christian on the Island. Thirdly, The smoke monster told Ben to follow Locke's every word. The smoke monster is Black so i think it could also be on the Nemesis side.
The only problem I see with the Nemesis plan to use Locke's body was that Jacob had already been in contact with Jack, Kate, Hurley, Sayid, Jin, Sun, & Sawyer, and for Locke's dead body to come back he needed them to come back too. I believe that Jacob's contact with Jack, Kate, Hurley, Sayid, Jin, Sun, & Sawyer has made them like Richard, immortal, and because of this when the bomb went off they were all saved.
Before Jacob died he said to Locke 'they're coming', i don't think he was referring to Illana's gang but to Jack, Kate, Hurley, Sayid, Jin, Sun, & Sawyer who would have had 30 years Island experience since 1977. I think this is backed up by the look on Locke's face when Jacob said this. I also think it would make a great twist as it would mean that Jack, Kate, Hurley, Sayid, Jin, Sun, & Sawyer have been on the Island since season 1 episode one in the back ground monitoring themselves.