He never learns Leia's name.
Only at the end does he realize Luke even had a sister. I'm not sure if he realizes it was the same person he tortured in Episodes IV and V.
He learns of the rebel who destroyed the Death Star being named Luke Skywalker and realizes it is his son. He denies it later when the Emperor confronts him with this, but only because he wanted to use Luke to overthrow the Emperor.
You'd think Luke would have had his name changed to Lars, you know, seeing as the idea was to protect him and all.
Somehow I fail to see how keeping his name as Skywalker would benefit his protection and anonymity.
Or did Obi-Wan and Yoda intentionally conspire to have Luke become famous, and have Vader seek him out? Bah, conspiracy theories are no good when its pretty damn obvious it is yet another plot hole. Doh!
Originally posted by yerssot
that's cause if there is ONE planet Vader wouldn't go to, it would be Tatooine considering his mother died thereand to keep him named Skywalker was probably to get Vaders attention so they try and turn him back to the light side or something
And don't forget he's going to live with other skywalkers...so his name would naturally be skywalker...
Oh dear, score another plot hole right there.
Vader's new line is "How is that possible?" when Palpatine reveals that the boy is likely to be the son of Anakin.
And yet Vader has been desperate to find young Skywalker for some time before the movie even begins, according to the opening scrawl.
The new edit is completely out of synch with the plot. Oh dear.
You have to remember that given Palpatine's overconfidence in seeing how things will turn out and that he has Vader under his complete control, he isn't going to be concerned with what Vader is doing behind his back.
Vader being a Sith, he has from the moment of his turn been scheming to be the Master and control the galaxy. The line "the force is strong with this one" and then finding out he is a Skywalker, he knew he had found his son and apprentice in which to help overthrow the Emperor. He proves this on Bespin.
Now, here is where it gets tricky. Vader says if he could be turned he would be a powerful asset or something like that.....RED FLAG HERE...since there can only be two, each of them would then know what to other was up to. UNLESS.....the rule of two had been abolished since there was no need to hide their numbers to get revenge on the Jedi...but why wouldn't there be more than just the two by that time. If anything, there is your plot hole, but by that time I think it became a chess match between Vader and Palpatine to see who could turn Luke to their side.