Although much has not been revealed about the game, Halo: Orbital Drop Shock Troopers faces stiff resistance in the hands of Killzone 2 which looks to have a more robust formula for reshaping the thought flow of console first person shooters.
Halo 3 stood its ground at a time when it practically had nothing to compete against, but times have changed and with growing expectations it becomes rather difficult for a game like orbital drop shock trooper to be a valued in a sea of shooters that seem to offer a lot more than the tag of a coveted franchise.
ODST places you as a side hero in the timeline which might not be accepted by too many gamers, this is reasoning has been put forward by the reactions players had after being forced to skip playing as the Chief in Halo 2 and being put in the shoes of the Arbiter in every alternative area.
Halo 3 specifically addressed this by reworking the mechanics to focus back exclusively on Master Chief, where perhaps the entire joy of Halo actually lies. A sudden transference of power equations to a much weaker character may not go very well down with the audience.
Since this is a budget title a very tight team is working on the mechanics of the game, while Bungie focuses on bigger projects at hand. This gives ODST a smaller sense of the scale and hype than Halo 3 bathed in.
Microsoft also seems to be heading towards cost cutting procedures which translate into a significantly lesser amount splurged on marketing and advertising, thus providing no more "fuel" to funnel the "fire".
Players are still running amok with Halo 3 online, the single player concern for the Halo franchise has been minimal. It has always been the multiplayer front that has shown players the true nature of combat.
With the scheduled "Mythic" pack hitting shelves in a couple of months, it provides very little incentive for players to shift their loyalties onto a newer franchise especially when the older packs quite a wallop.
A sub $20 price point may not prove sufficient for ODST to wrest the crown as a notable first person shooter in 2009, unless the developers are actually looking to create a side story franchise with characters they can introduced in Halo 4 like they did with Half Life Opposing Force and Blue Shift. More PlayStation 3 News...