I think Stardock should consider making a City Building Game that is set in the future, instead of highways you called have hyper highways that can speed up the base speeds of the hover cars (kind of like an artificual jet stream that can run anywhere in the city). Instead of subway's you called have the tube like thing from futurama.

You called have contracts with the military of the planet to design and build ships for the empire! (using something similar to the Ship creator in Gal Civ 2)

Have landmarks that ain't been built yet (The Space Elevator, The Universes tallest Building etc.) I think it walled be real cool especially if it was made similar to Sim City 4 (in that it can be changed in dramatic ways just check out the simtropolis community and what they have accomplished)

You called have to build massive powerfull weapons (like an ion cannon) to defend the city against a planetery Invasion.

It would also be cool if you called desighn buildings real easy! (a real simple architectural tool)

And of course with the originality, creativity and the overall spark stardock could give it would put the icing on the cake!