Halo 3: ODST

Halo 3: Recon is a campaign expansion and prologue to Halo 3.

Overview
Although Bungie has consistently stated that Halo 3 was the last game in the trilogy, having ever ruled out possible Halo games in the same story line being released in the near future, an interview by MTV with Don Mattrick (Senior Vice President of Microsoft's Xbox division) revealed that Bungie's game is at the very least Halo-related, and that it is not Bungie's collaborative efforts on Halo Wars or Halo: Chronicles, but a "new" game.

Although a proper announcement was meant for July 16th, 2008 at E3, it was canceled by Microsoft because they wanted to focus on games by first-party developers that were coming out in 2008 - criteria which the Bungie project did not fit. It was also stated by Microsoft that they did not want to further lengthen their press conference so as not to stretch the attention span of the attendees, and that they wished to give the new Halo project an event of its own to release details on it. The most popular rumor surrounding this new title is that it's a squad-based shooter in the Halo universe with the player filling the role of a Marine Captain. This could be the reason why Christian Allen, a former Marine and Red Storm employee who worked on the Ghost Recon and Rainbow Six series, joined Bungie in early 2007. As of October 8th, Bungie has confirmed that the player will take the role of a surviving ODST, that it is set in the ruins of New Mombassa, and that it will be released in the US "Fall" of 2009.

In a section of the video, what appears to be random letters and numbers contains the date "January 6, 2009." As this is well before fall, it seems an unlikely release date, but a significant date nonetheless.

On Xbox Live Market Place, Halo 3: Recon has been described as 'Halo 3: Recon returns players to familiar ground on a vital top-secret mission. Recon's gripping story, co-operative campaign and new multiplayer content will have Halo fans 'Prepare to Drop' in Fall 2009'.

Trailers
First, different screens of areas of New and Old Mombasa come on screen, followed by HEV pods entering the atmosphere. Here you can see the Prophet of Regret's carrier on the right, then it moves behind buildings. The pods come into view as a large EMP explosion (Caused by the Prophet of Regret's carrier entering Slipspace) appears, sending the pods off-course. Then, the Superintendent appears, and shows warning signs and then reboots. All the screens from earlier flash onto the screen, but heavily damaged from the blast. Then, a single HEV pod falls through the sky, when the Halo 3 Logo appears. The pod then crashes into the camera and goes black, followed by the words 'Prepare to Drop'.

The second part to the trailer, released on the 8th of October, followed on from this - the Superintendent reinitializes itself, attempting to assess the catastrophic devastation and identify the object that survived. Later, after a Covenant Phantom dropship has passed by, the object opens to allow a surviving ODST to clamber out, wielding a new variant of the M7S Caseless Submachine Gun with silencer attachment. The ODST narrowly avoids a Brute patrol, before encountering messages from the Superintendent, presumably leading him to safety.

Trivia

 * A teaser trailer for Keep It Clean was released at 07:07:07 am PST on September 25th, 2008, the one year anniversary of Halo 3. The trailer was viewed through the many security cameras around New Mombasa. Also an obvious reference to seven.
 * When "Halo 3" is displayed in Conduit ITC, by slowing down the video someone can see the words : "Activating sub-routine “Vergil". Warning, Data Leak on Level 9"
 * When the camera switches to the street with the 2 cars before the blast, it reads in the right corner: SIERRA117 LOC LINK 0x2F278609. It seems that the Superintendent is looking for or displaying John-117's coordinates.
 * The game's main character will likely be an ODST in the First or Second Battle of Earth, during the Brute invasion.
 * It should be noted that the ODST is carrying an M7S Caseless Submachine Gun, a weapon not seen in the Halo trilogy.