If you cant get down to argos I found this.
ODSTs: Follow the story of the legendary ODSTs or Orbital Drop Shock Troopers as they drop into the ruined city of New Mombasa, looking for clues behind the Covenant's catastrophic attack on the city.
A new hero: Prepare to drop. Known for their courage, valor and at times, insanity, Orbital Drop Shock Troopers are among the fiercest UNSC soldiers, priding themselves on being the first unit deployed into hostile situations.
Run and gun: While not as large or supernaturally gifted as their Spartan comrades, these Hell Jumpers more than compensate with their ferocious attitudes and unwavering nerve.
Multiplayer: All the traditional features of Halo 3 multiplayer will be included in the new game, including full-featured integration with the Forge map editor.