Are we desensitizing our children to gore and violent images in the name of Halloween?

Well that is your choice. If you don't want them to look at that then don't. But I think that as long as they know that it is not real or will not hurt you, then there is nothing wrong. That is just like telling them that a dog or cat will not hurt you and that you don't want to be scared of them. Children are going to be exposed sometime or another to bad things, its just how it is. Its just a fact of life. You cant keep your kids sheltered from life in some realistic bubble.