Who wants a game you can beat in 5 hours of play?
Heh... I meant that it sounds awesome, but would also be a lot to have on your plate for development.
Personally, I'd go for some sandbox elements in there. Start a player off in whatever faction, as whatever class, then have the game progress from 3050 onward, with the factions under control of the computer. So, according to a players actions, whether they win or lose changes the war [but doesn't end the game.] and allows them to fight again in a different place and time. [Perhaps even make it so you can 'become' a new person when you die.]
Procedural gameplay like that could make the singleplayer campaign much, much more enjoyable and replayable in the long-term. Though a big problem that I can think of right now would be generating good missions for a player. Procedural stuff tends to lack the kind of depth that a hand-made encounter might have. In which case, I think a combination of the two would do well: Hand-crafted battlegrounds for particular planets of interest, while the backwater areas have procedural missions.
Anyways, that's just some of my idea for a splooge-worthy mechwarrior campaign. [Maybe Dwarf Fortress is corrupting me.] But I know it's a lot to chew on, even for experienced developers.
