I don't think that bit would have had quite as much shock value that Darth Vader being Luke's father did but I do think it could have lead to all kinds of interesting storylines.
Vader could be lying certainly....
He could be telling the truth, but then was Ben lying outright and why?
Maybe Anakin was drawn to the darkside by Vader and so from a certain point of view it was Vader who killed Anakin while Obi-Wan just killed the Sith he had become.
Does anyone else find this stuff interesting? I keep thinking I'd like a new RoTJ "Infinites" storyline to take a shot at it.
