Children have grown up through War, Disease, and Violence of every kind .. if they haven't been desensitized yet then I doubt some candy and a can of fake blood is going to do it. Kids, and the community as a whole, have an ever developing taste in what is Creepy, Scary, or Fun.
A kid in the 1910 may have gotten a thrill out of a Bedsheet hanging from someones tree, but in 2010 with all the technologies and special effects they are exposed to -- its gonna take more than that.
I wouldn't mind taking my child to a house with blood splattered on the door and what ever -- its Halloween -- its make believe. Halloween is probably one of the most Policed and Safest nights of the year
"I have always thought of Christmas time, when it has come round, as a good time; a kind, forgiving, charitable time; the only time I know of, in the long calendar of the year, when men and women seem by one consent to open their shut-up hearts freely, and to think of people below them as if they really were fellow passengers to the grave, and not another race of creatures bound on other journeys." ~Charles Dickens