Wow, interesting right. Wow was definitely what I was thinking this when I first saw this on IGN.
Well now yes, Bungie has decided to officially change the name Halo 3: Recon to Halo 3: ODST.
The ODST is an acronym for "Orbital Drop Shock Troopers." These elite soldiers will be the focus on the upcoming game and the tale will be told from their perspective rather than Master Chief's says IGN.
IGN and many other people were curious on why Bungie changed the name so IGN decided to contact Microsoft and a representative told this to IGN:
We decided that "Halo 3: ODST" was a better name for this title as we look to build out this new character and the story behind the title."
Here is a link to the page on IGN where I first found this nifty information:IGN: Halo 3: Recon Name Changed