I remember GalCiv 1's missiles. They were like ships who died right after the first strike...
Why not doing the same kind of thing for GalCiv2? the "missile" arrays would be able to launch from 2 to 4 missiles before reloading (either every turns, or in the vicinity or a planet). These "missiles" would be like mini-ships, and who would "live" only 1 turn (the same one it had been launched), and be allowed only 1 free attack, with no retaliation possible (except maybe other missiles...)
It could add a tactical dimension on the whole map without having to re-design the battle engine. Missiles would be weaker than actual ships, but you could harass ships from a safe distance, or even outsite your maximum range..
Need comments and suggestions!