Not directly Marathon/Bungie related, but I thought this was of interest.
Recently when looking up information about the upcoming Rainbow Six game, R6: Patriots, I watched an interview with the game's project lead and writer, Richard Rouse III. The man's name seemed familiar, and I recalled that he either used to work for Bungie or had something to do with one of their earlier games.
A quick internet search revealed that I was partially right. I had remembered his name from playing Damage Incorporated, a 1997 FPS/tactical strategy game using the Marathon engine (currently freeware, I believe, for anyone who wants to try it out). Having just watched the interview, I recalled there were similarities between the premises of both games.
Both games, tactical shooters with a heavy emphasis on fireteam-based planning and action, have you as the field commander of a counter-terrorist military force pitted against a domestic terrorist group composed of various extremist political groups and militias, all led by a disillusioned veteran of a war who wants to overthrow the US government. According to an interview with Mr. Rouse, he suggested that a possible sequel to DI would include a fair bit of moral dilemma and tough decisions in game. From early trailers and interviews, Rainbow Six Patriots will include tough moral decisions and ambiguity as a major feature of the single-player campaign. I wouldn't be surprised if there are a few callbacks to DI in game.
Just something I found interesting...
Here's links to the interviews I referenced:
http://paranoidproductions.com/damage/interview.html
http://www.gameinformer.com/b/features/archive/2011/11/11/rainbow-6-patriots-advancing-the-narrative-in-shooters.aspx