Add a chase cam to siege projectiles
Part of sieging is aiming and powering, this would make it far to easy to do both. There are times when that 1 or 2 shots that are off the mark makes a difference for those attacking/defending. It would also give you the advantage of seeing enemy numbers, and siege placement within the structure, now you can just aim and kill all the defences. Lets not make this game anymore easy.
Although it would be hilarious to gank you while your watching rocks fly.
According to Anet, that kind of thing would probably take a year to put into the game.