Something occurred to me in catching up with this thread.
I'm speculating that the Monster Fighter line was a mixed success for LEGO, definitely not the big seller they might have hoped it could have been. But with the HH continuing well past the shelf life that MF is having maybe LEGO will consider a one-a-year big exclusive Halloween based set much like the one-a-year released Winter (Christmas) themed sets that seem to do well. If the HH production lingers into 2015 then maybe another Halloween exclusive will be released Sept. 2015 and a new one every Sept afterwards. This might be a better way for LEGO to tap into that pent up Halloween product demand without committing to a wide spread line of releases like the MF was.
Ultimately, hopefully, we can see things like a 'Haunted Graveyard', 'Abandoned Keep', 'Witch's Spooky House', 'Haunted House II' being put out year after year!