Okay, this logic is fine with me. I have no problem with it. However, the new dialogue jumps out from the film as needing an explanation like this (Vader's reaction feels out of place which is why so many people are asking) whilst the original lines didn't leading me to wonder what Lucas felt was missing from the original lines.
Obviously one new element is the reference to 'Anakin'. Along with adding HC to the end of RotJ, this is clearly Lucas just trying to reference the prequels, for better or worse. That's fine, but making a point of Vader lying to the Emperor seems to only confuse issues further - issues that have only been brought about since the invention of the 'only two' rule.
Just for reference, here is the original dialogue from Drew's -
Quote:
VADER: What is thy bidding, my master?
EMPEROR: There is a great disturbance in the Force.
VADER: I have felt it.
EMPEROR: We have a new enemy -- Luke Skywalker.
VADER: Yes, my master.
EMPEROR: He could destroy us.
VADER: He's just a boy. Obi-Wan can no longer help him.
EMPEROR: The Force is strong with him. The son of Skywalker must not
become a Jedi.
VADER: If he could be turned, he would become a powerful ally.
EMPEROR: Yes. Yes. He would be a great asset. Can it be done?
VADER: He will join us or die, my master.
As it is, it is ambiguous enough. Vader is neither confirming nor denying that he already knew of Luke's existence and was searching for him. This, in my mind, was a far safer gamble as, earlier in the film, we see him mention Luke in front of many Imperial Officers - not all that clever if Vader were to lie outright to his Master about it. In fact, it would be downright idiotic. Seeing how switched on Palpatine is, it is exceptionally unlikely that he didn't know what Vader was up to.
But then, now that I'm this far into the post I'm realising that, once again, these are only issues because of the retrofitting of the films to work with the 'only two' rule. This conversation and also many others in RotJ all worked fine and the end of RotJ was clear as day until someone (not sure if it was Lucas or if it was an EU thing) invented the 'only two' thing. That the Emperor needed both himself and Vader to turn Luke (beginning of RotJ) made perfect sense. Now it requires big long explanations as to who is fooling who and requires a lot of reverse engineering to watch the movies without going 'wtf?'. It brings up the questions we often see like 'why Vader bloked Luke's lightsaber swing towards the Emperor in RotJ?' and the question that started this thread.
I'm beginning to realise that, like midi-chlorians, I may have more piece of mind if I deny the 'two' rule completely. After all, if Sith Lords are so crafty and untrustworthy, how could they be expected to stick to such a ridiculous old restriction? Hmmm, yeah, this is really one of those things where I think Lucas should be changing the prequels to fit the classics and not the other way around. I'm loving my clean, crisp, dvd transfers and think the movies looks better than ever but I'm really finding myself on the side of the people who think the more Lucas 'fixes' the more he breaks.
Dogg.
Edit: Just one more thing on the subjects of Sith Lords not telling the truth (brought up in the second post) - well, maybe not to each other, but Vader told the truth to Luke, Dooku told the truth to Obi-Wan and the Emperor was fairly straight with Luke too. Compared with Obi-Wan's constant lies in the OT, the Sith Lords seem pretty trustworthy to me.