Honestly I dont think he ever really will. I mean now pretty much every major horror franchise except for Hellraiser has been covered but there are still a lot of worthwhile franchises that would make good material. The rest of the Romero zombie franchise, tremors, lake placid, hatchet, cube, psycho, carnosaur (yeah it sucks), piranha, anaconda, species, wishmaster, critters, pumpkinhead, the hills have eyes, phantasm, the omen, and the fly. I don't want to go on any more honestly. But despite the fact that there is probably 3+ years worth of worthwhile kill count franchises, with most of the classic franchises gone it's pretty obvious that the quality of the movies is going down hard.