It was revealed today that Halo: Reach will finally see a release on the Xbox One and PC on December 3rd. Part of the Halo: The Master Chief Collection, the game is set prior to the events of Halo Combat Evolved.
This will also be the first time the series will be available to purchase on Steam, you will be able to purchase the game as a stand alone title for $9.99 or as part of the Halo: The Master Chief Collection for $39.99 with the later titles to be released later.