While it is rather early for that, already there are two venues of modding availvable (and really, if things won't go horribly wrong, I think there's bound to be at least some interest in modding something with such simple concepts):
1) Mega File editor as of now is does support 8-bit armies (v.1.3).
Correct me if I'm wrong, but it seems that extensions of the files are the same as most PGs games (e.g. .alo for models).
2) And now for something more official. In short, it is now possible to have custom unit responces.
Oh, while I'm at it: with the growth of game the amount of audio files will also grow: it's already 165, and I don't think this number will shrink for other factions. So I'd like to suggest this: add another folder in this chain, FACTION# (e.g. 00 or 01 for "Renegades"), so that all files would be neatly organized.