Absolutely terrible ending....
Sara deserved a better ending than that, to have the final shot seen through the perspective of a minor character. In general, what an anti-climactic ending. That's really the best they could do? The film had a decent build-up, but that was one of the most unsatisfying, "bleh" endings I've seen in a horror flick....and I've seen my fair share.
EDIT: "The Witch" has now taken over as most unsatisfying ending to a horror film I've seen.