What would you make it about, and what type of game would it be?
Personally, I'd love to see a relaunch of X-Wing/TIE Fighter with modern graphics. My preference would be to set it in the period just before TFA and focus on Black Squadron (at least for a story, online you'd just have a bevvy of spacecraft to pick from and could make your own squadrons up).
I know they have space battles in Battlefront I and II, but those are "arcadey", I want one that is much more flight/dogfighting sim.