Ultimately this depends on bandwidth and where they could ultimately go... I figure Orbital Arm makes the most sense... but hear me out.
I'm preparing and testing stand-alone windows installers for the Trilogy and most of the major 3rd party scenarios. These installers are download and double click on windows, and VOILA, you have a working game. They include custom icons for the EXE, custom icons for the data files, 256x256 hi-res textures, and the simplicity that a download and double click installer can give.
I've got what I consider to be a working system (obviously, some file names needed to be changed to get custom icons for the data files, but I've spent beaucoup time adjusting all my mml scripts), but before I start to produce installers for all the games and scenarios, I would love if somebody else would beta test to make sure that there are no snags. Marathon 2 is the testbed. So, if you're on windows and want to help, send me an e-mail at jorge-at-salasnet.com. I'll take 2-3. Preferably... I would like a mac/windows user like myself who has some history with the marathon series. :-) (no tBC (BattleCats) allowed!)