ODST uses the same engine as Halo 3 so i believe that we will be able to lower our weapons.
You say Red vs Blue... don't you mean machinima in general?
Anyway i don't think there would be a red vs blue series using ODST as there are no spartans.
This means that there would be no Caboose, Tex, Tucker, Church, Donut, Sarge, Grif, Simmons, Washington, Flowers, Sister or anybody who are loved characters in RVB