It’s true, as you can tell by the image above, Halo 3: Recon has been renamed to Halo 3: ODST, Bungie announced today. This is because in the game, you play as an ODST trooper.
“ODST” (literally pronounced “Oh-Dee-Ess-Tee” and not “ohdst”) is the acronym for “Orbital Drop Shock Trooper.” This special forces branch of the UNSC military force is called into action for highly specialized, small scale operations. ODST units were deployed during portions of the Halo 2 and Halo 3 campaign and have also been featured in some of the Halo novels. To learn more about this elite military operation, check out this recent interview with Bungie’s Halo fiction guru, Robt McLees.
Halo 3: ODST hits stores next Fall and the Mythic Map Pack for Halo 3 will release on the Xbox LIVE Marketplace sometime early next year.
Halo 3 : ODST [Bungie.net]