I was typing a post on a certain other toy board when I hit upon a point which I don't think has been made before about the implications of the redone Emperor hologram scene in ESB. I immediately discontinued my post, knowing that it would probably be a waste of time over there anyway considering they all seem to be kids nowdays whose ability to comment doesn't go beyond words like 'Sweeeet' and 'that sux ***'.
Anyway, as we all know the opening crawl of ESB states that Vader is searching for luke skywalker and one of his earliest lines in the film is 'that is the system and I am sure Skywalker is with them...' - this applies to all versions of the film from 1980-present, including the DVD. So we were all surprised when the DVD edition, in spite of these details, later has an altered scene in which Vader appears to be taken aback when the emperor tells him that Luke skywalker is the son of Anakin/Vader. 'how is that possible?' he says. Curious. Did you think it was just a coincidence that this force user you're looking for has the same surname as you, we wondered? Not wanting to believe that the great Darth Vader was actually a bit thick we fans came up with the theory that Vader was merely feigning ignorance to the emperor. We assumed that after his encounter with Luke in the death star trench Vader did some private investigating and uncovered the truth himself before the emperor hit upon the idea of mentioning it to him. And it doesn't seem out of character for Vader (and a sith) to keep things from the emperor (his master) or have aspirations of overthrowing because he says as much to Luke at the end of their Bespin duel. Meanwhile ROTS tells us that this started really early in his sith career when he makes an offer to padme to rule the empire with him. So thats all tidied up then. Isn't it?
My point is - just how 'private' did Vader keep his investigation into Luke? Because it seems he has no qualms about blurting out about his personal quest (referred to in opening crawl as an 'obsession') to his underlings. At least 3 different imperial officers (Piett, Veers and Ozzel) know that Vader is looking for a guy called Luke Skywalker amongst the rebels. If he wants to keep it from the emperor is this wise - is he thick after-all? Or does he not particularly care if the emperor finds out? Could he have hoped to have successfully coerced his underlings into keeping quiet? How much were we supposed to read into this?