Originally posted by: Marvolo
Vader would not try to kill luke once he found out who he was because he wanted luke to help him kill the emperor in th next movie. It would create bad continuity.

I dunno. In the death Star trench he could panic and want to kill Luke but later he has time to think 'maybe I can benefit from hime being around'. And I like the idea of a 'later' scene in which the Emperor confirms that the boy who destroyed the death star was Anakin's son (as opposed to some random dude also called skywalker). This is all good stuff IMO.