While I recognize that this may be far off (I mean really, really far off), I think it's good to bring it up now in considering the future.
Perhaps at some point Arcen will start using a new engine and an AI War 2 will come out, which means that the final expansion of the first game could potentially only be a few years away.
Regardless, the reason I bring up this thread is that I think there's an important feature that AI War lacks, and that could improve the quality of the game dramatically for the community, and that is the ability for modding.
Now it's quite clear that the developers have been hesitant to add this, because they feel it will divide the community with so many different mods being created for the game, and would rather design/balance things themselves based on community feedback. However, Arcen is a busy company, and after many years and 6 expansions, AI War is a HUGE game. Even if, with limited manpower, they were devoting all their time to it, it could still take years to address many of the design and balance issues that have arisen over the course of so many expansions and MASSIVE design shifts.
Which is why I recommend that the ability to mod the game be added to the final expansion, since after that, it will become the player's game anyway. Sure, it may be somewhere down the road (how far, it's impossible to tell). But I thought it would be nice to begin discussing it now, so we can think about the implications of it.
Personally I think AI War is one of the most mod-friendly RTS games of all time. Just changing a few numbers on a spreadsheet, you could alter the entire game experience. Also, AI War lends itself to so many different personality types and playstyles that the ideas and variations on the game are practically endless. I think that if we allowed modding, we would see an explosion of awesome mods and redesigns that would surprise everybody. Don't forget about all the cool new ships and weapons that would certainly make it into the game as well ;p
Anyway, just keep it in mind.