Halo 3: ODST was pretty much a success for Bungie. However, there has not yet been any indications that the developer is interested at all in putting out more of these adventures of ODST. What this means is that he really does not have any interest in putting out any downloadable content. This game was just a one time only sort of thing. We have not, however, seen the last of the characters that were introduced by Bungie in Halo 3: ODST. In a interview with Bungie after they had released the game, Joseph Statten, who is both the writer and the creative director, mentioned something about Buck. Buck is voiced by the actor Nathon Fillion.
“I can’t comment on any future plans for our ODSTs,” said Statten. “But it would be a shame if we made a game about the planet Reach — a place where Buck, the ODST’s squad leader, was known to be — and not have him appear in some way shape or form…”
All that is being said here is that Fillion will have a role in Reach because Buck is for sure wanted to come back.