Maybe for reasons of faith, maybe because "spooky" is fast becoming "bloody," doesn't it seem like a lot more families are veering toward the generic harvest celebration? Even this month's Martha Stewart Living seems to minimize the Halloween theme -- saving brilliant ideas like the eyeball highball for a separate special issue -- in favor of bobbing for apples and squash bowling. Positively Rockwellian.
However you celebrate, Seth Godin calls this a sort of "secular Christmas" -- "the only holiday (perhaps in the world) where there is an arms race of creativity. Every year there's new stuff, new ideas, new ways for yuppies and boomers and everyone else to spend time and money." But I think this is instead part of the Christmasization of all holidays. (Do you have an Easter egg tree? Thanks for proving my point!) We want to decorate and celebrate year-round because it can be more fun and less manic than Christmas decorating and celebrating.
Also, unlike Christmas, we can wear other seasonal sweaters without fear of ridicule. Can't we?