theslime, I usualy agree with your Hitchcock reference (often say it myself in fact!). The audience knowing who Vader is and not Luke is obviously the option Lucas choose. It's not a totaly bad thing, indeed, it brings new "point of view", and possibly more suspens. And it is also true that by 2009 (soon 2010) almost everybody who like movies in general knows the line "No, I am your father" even if they did not watch Empire!

The fact is that in this particular case (the revisited Adywan versions) I personaly feel that everything needs to be done to preserve the original trilogy as much as possible. If surprise was a key element in Empire, I'd prefer it to stay an element of surprise.