From Halopedia, the Halo wiki
Real World Events
- April 15: The Legendary Map Pack for Halo 3 is released.
- July 14: The Five Long Years Cinematic trailer for Halo Wars is shown at E3 2008.
- July 15: An apology message about the postponing of the announcement of Bungie's new project, which was to be shown at E3, is posted at Bungie.net. The project would later turn out to be Halo 3: ODST.
- August 13: Issue 3 of the Halo: Uprising comic book series is released.
- September 25: The "Keep It Clean" trailer for Halo 3: ODST is released.
- October 8: Halo 3: ODST, then called "Halo 3: Recon", is officially announced at Tokyo Game Show 2008.
- November 25: The Art of Halo 3 and Halo: The Cole Protocol are released.