Atari has assured us a playable demo for Alone in the Dark is still coming to Xbox Live Marketplace.
"The Alone in the Dark Xbox 360 demo is currently being finalised," the company said in a statement, "And will be available on Xbox Live Marketplace in the coming weeks."
Still no specific date, then. But you could always just buy the game, seeing as it was released for PC, PS2, Xbox 360 and Wii on Friday. The PS3 version is out the autumn.
To find out whether it's worth the money, you could always read Tom's review.