One thing we are looking at is at the end of the turn move the asteriods randomly in some direction, makes life exciting.
i think FF may introduce something like this as part of a future wave. seems a little unrealistic that all asteroids hold their exact position the entire game. some house rules are changing this for casual games so if u think ur local playgroup wants it then implement something.
it might even be possible to destroy asteroids altogther and either inflict splash damage on nearby ships (range1) or just remove the obstacle.