hairy_hen said:
Simple: don't show it.
More easily done by having Anakin Skywalker not be the main character, and occupy less of the focus. Neither would Obi-wan exclusively be the protagonist, so that the fight which leads to Vader's need for the suit of armour isn't really shown either. This allows Anakin to 'disappear' from the story, say at the end of Episode 2, without being fully explained; and Vader to appear as a menacing and mysterious villain who hunts down and destroys the Jedi in Episode 3.
I disagree with you, for a number of reasons.
First of all, you don't have to watch the star wars movies to know the plot twist in star wars Episode 5; I know lot's of people who wouldn't exactly be considered "geeks" or "nerds" and they have never even watched either the PT or the OT. So, there's really no point in trying to hide the plot twist.
Second of all, Darth Vader/Anakin Skywalker being the protagonist of the star wars movies trilogies actually kinda sounds like a good awesome idea, the idea that George Lucas had. "The tradgedy of Darth Vader". The whole idea is that it aint Luke Skywalker's story, it's his father's story, so the whole thing shouldn't be a suprise to us, it should be a suprise to Luke skywalker.
Also, the Mustafar lavaland immolation scene where Lord darth Vader gets all burned up and bald and then gets put into the cyborg samurai black armor robot suit, that scene was my most favorite scene in all 6 of the star wars movies/films, the best most awesomest scene ever of the entire Prequel PT trilogy!!!!!!! Why???? It showed us Darth Vader without the robot suit, and most of all, the transition from human to a half-man half machine. From
To
I love cyborgs in science fiction, and their physical transformations are the coolest part about them. Editing out the Mustafar lightsaber fight/duel and the burning immolation scene in the lava and the subsequent physical operation on Coruscant into the cybernetic black knight with the samurai helmet and the deep james Earl Jones/mechanical robot breathing would basically be editing out the most awesomest part of the entire series/saga........