AH currently has only 1 light source that emits 'lighting effects' such as glare, flash, tone, shadows and etc., and that is the sun. You won't be able to notice a Cruiser firing its big guns at a distance of 1000 yards if it were not for the tracers.
I'm not quite sure if adding more lighting effects would seriously hit the fps rates, but it sure would be nice to be actually able to see enemy fire at distances further than 200 yards or something.