I've been thrilled by the idea of space based strategy games since playing Star Control 2. However any RTS combat is pretty lame. Home World seemed cool but quickly became another tank rush affair with a 3rd dimension of movement. I lost interest in this game too. Where as the RTS combat in something like the Total War series is excellent. The main difference is terrain.  I think "terrain" matters in Space too but you need to model it.  I want to see ships in orbit around a planet where different types of ships are faster at changing orbit than other, where key high ground places are Lagrange points. Other advantages or disadvantages depending on where in orbit you are. Perhaps pressing a button will show an overlay of the gravitational contour lines (see wiki link below). Movement is a dynamic process, where all bodies have a trajectory and you need to plot rendezvous points with the aid of an intuitive UI. Real space combat would be very complex so there is plenty of richness there to bring into a game. Not these bad space invader affairs that haven't really evolved from star control 2 at all. Hell at least Asteroids modelled momentum pretty well.  It just surprises me the lack of imagination in what's on offer currently.

http://en.wikipedia.org/wiki/Lagrangian_point