Halo Wars announcement trailer

The Halo Wars trailer was revealed on September 27, 2006 at the Microsoft X06 media briefing. See it here on youtube.com

X06 Trailer
The trailer shown at the X06 began with an Ensemble Studios logo, followed by five M12 LRV Warthogs and two modified (turretless) Warthogs leaping over a rise in a snowy night landscape. Two Marines from the outfit Blue 6, dressed in Arctic uniforms that haven't been seen in any other Halo productions before are radioing in to Spirit of Fire, confirming their joining with Blue 5 (an outfit of five M808B Scorpion tanks) and their trajectory towards the last-known position of the recon force with whom communications were severed. The camera then pans to two members of the recon patrol that seem to have re-established contact, as they radio in to Blue 6 as they flee from an unidentified figure towards a waiting Warthog. Both Marines, however, are promptly gunned down by plasma fire, with one man surviving long enough to turn on his back and witness an Elite uncloaking. Screams are heard over the radio, and it is revealed that the last remaining patrol member has been killed. The Elite picks up the carcass and inspects it, after which he tosses it aside. Additional Elites uncloak behind him as eleven Banshee jets rise into the air and charge forward. All-out battle breaks out as several previously unknown dropships land which might be updated versions of the UNSC Albatross;accompanied by C709 Longsword starfighter's, unidentified UNSC fighters, Scorpions, and Warthogs are deployed along the line. A wing of Banshees is shown wreaking havoc upon the UNSC air force, but several Marines taking cover behind an overturned Warthog are able to gun down the leader of several charging Elites with what appears to be Battle Rifles. The camera then cuts to an over-the-shoulder from behind a Spartan, which reveals that the battle has already progressed to a point where several columns of smoke are rising from the destruction. The Spartan then identifies himself, along with his 4 Spartan squadmates as Spartan Group Omega. Their armor seems to be a modified version of the Mark VI MJOLNIR, with the plate armor being more reminiscent of the armor seen in Halo 2 than the armor seen in Halo CE, albeit with a modified mouthpiece. The Spartans all seem to be carrying Battle Rifles. They give a bravado-charged "If they want a war, we'll give them a war", before the screen cuts to a Halo Wars logo and the trailer ends.

Music in the X06 Trailer
The music begins with a restless violin section almost reminiscent of the music omnipresent the the Matrix series. The music then shifts into a triumphant, driving drum beat that takes a distinctive minor turn when the recon team is gunned down. When the surviving recon soldier is stabbed with the energy sword, perhaps the most recognizable piece of music is heard: the Gregorian chant section of the original Halo theme song is reworked into a mournful section that depicts the hopelessness and despair of the fight against the Covenant. As the Elite tosses aside the body, the music takes a distinctive modal shift into what sounds almost Middle Eastern, but immediately shifts again into what sounds increasingly reminiscent of the beat-driven riffs of Martin O'Donnell of the Halo series, perhaps hinting that he has been working with the Ensemble team, and indicating an increased level of collaboration between Bungie and Ensemble. After a desperate violin arpeggio, drum beats accent the brave words of Omega Leader, and the trailer ends with a simplistic low note that seems to be inspired by the simple tones of the Halo 3 trailer.

Inconsistencies
Several inconsistencies have been noted between the Halo Wars trailer and the rest of the Halo series.


 * Despite the fact that Halo Wars takes place before Halo: Combat Evolved (some time between 2525-2552), all the Marines as well as Spartans are using Battle Rifles in combat, which aren't introduced until the Halo 2 section of the story (and even then in supposed "experimental testing")
 * The MJOLNIR armor worn by Spartan Group Omega is clearly a modified version of the Mark VI armor from Halo 2, but once again, this story arc takes place before Halo: Combat Evolved. In the time period in which Halo Wars takes place, the Spartans were using Mark IV armour which had no shields and no AI-holding crystal layer.
 * The Banshees are either modified or a different model, as they have a ridge on their hoods and even feature headlights, as well as several individual LEDs on the engines instead of the faint glow from Halo: Combat Evoled. Regardless, the Banshees seem much more advanced than they should be, as they exhibit several features not seen in Halo: Combat Evolved.
 * The Banshees no longer leave a pair of contrails, and move at an unprecedented speed without boosting.
 * The Elites' combat armor not only exhibits the small LED-like lights seen only in Halo 2, but also shows the signature energy shimmer of uncloaking that wasn't present in Halo: Combat Evolved, in which decloaking consisted solely of the Elite fading into view. This may not be a technological change on the part of the Covenant; it could've been a technical consideration for developers.
 * The Elite model seems to have undergone minor reconstructions to the Elites From Halo: CE and Halo 2, appearing more bulkier and feral. And along with the familiar sound that the lead elite makes, the new design seems to make the Elites seem more like a Predator than ever before (The Elites structure, and 4 mandibles have often been related to that of the Predator from Predator, Predator 2, and Alien Vs Predator). The Elites Feet appear more Flat footed, rather than the usual Hooflike appearance seen in the previous halos. The Elites Hands are also more rough and clawlike in appearance, seen when the Lead Elite is inspecting the dead patrol member.
 * The cloaking technology of Elites has never been capable of masking the visible light emitted by an energy sword, but the energy sword is depicted as uncloaking along with the rest of the Elite as the recon soldier turns onto his back.
 * An additional peculiarity that, while it may not be an inconsistency per se, does merit mention is that many Elites are shown without weaponry; the leader of the group charging the UNSC line in the short battle section is shown simply running at the humans completely unarmed, and many Elites are shown decloaking with empty hands.
 * Although in the Background, the Hunters in one of the screenshots are seen as high as 20ft tall, despite the fact that they are in their combat stance.