If they do have a new maze this year, I would like to see it have a long, atmospheric build up with a really, really strong story-line followed by an explosive final.
Whilst quite common, a ghost haunting theme could work brilliantly! They could have sensors on objects in a room to move as you walk past, a few actors here and there but mainly relying on other effects and props. The final could have an actor (or several) who have been "possessed" by the spirit.
If just having one possessed person, they could be sleeping in the corner of the room, then as you walk past they could suddenly start running at you shrieking - causing people to run out of the exit.