According to a listing on the Marketplace, Fable: The Journey will be releasing on September 4th in North America, with the game to follow on September 7th in Europe. The date was spotted by CVG (those guys are always finding leaked release dates, huh?) on the official Xbox website.
As usual, the date has been changed on the website to show that the game will release on December 31st, 2799. While the quick change of date isn't necessarily an indicator that the September release is set in stone, accidentally leaked dates often turn out to be correct.
Fable: The Journey is an upcoming Kinect title from Lionhead studios. While Peter Molyneux has told the gaming press that the game is not on-rails, but it will be controlled using hand gestures and voice commands. The game is going to focus on casting spells rather than using melee weapons, and will be a bit of a departure from the traditional Fable experience.
Keep your eyes on GameRanx for more Fable: The Journey info as it becomes available.