The Aluminum Falcon said:
An aesthetic change I'd make is having Luke have a red lightsaber and Darth Vader have a blue light saber, having retrieved his old lightsaber from the duel on Cloud City. It would be like the "Revenge" poster and also hint at a change in the two characters. Vader going back too good and Luke possibly falling to the Dark Side. It would enhance the reverse symbolism greatly in the end duel...
I like this idea.