Yeah, I know I'm jumping the gun early, but this would have to be implemented early. No idea what the best way to make sure the honchos here see this, but I think this would be fun, and might help with profits (Which is what it's all about in the end)
My idea: customizable uniforms for your units.
I got this idea while playing SCIV, and thinking of Stardock's ship designer, and then thinking of a friend's artwork.
Why not allow people to dress up their elves? (Or the equivalent in this game) It doesn't have to be a bunch of breasts- and might be better if it's not, but why not allow people to design their uniforms from a wide variety of outfits? Everything from hakamas to suits of armor. Programming wise- I think the art would be difficult, but it should be a little simpler then your ship designer. One last suggestion, I'd suggest allowing users to submit art/modeling for outfits, and then throw that into patches (maybe make that seperate from gameplay patches) Would be a fun form of modding.
I don't know how feasible this would be given how you'll design your gameplay, but I can see this adding a lot of visual appeal, and would likely get you noticed more and draw in some people who wouldn't buy it otherwise.
The one thing I ask if that this doesn't impact gameplay in any shape or form, just for visuals/cheesecake/beefcake appeal.