Vader killed Padme.
Bang!
Simple. Easy. Classically tragic. And unbelievably, Lucas was too much of a wimp to pull it off. I have no idea why except that he still wanted the audience to like Vader/Anakin (even though he killed Jedi kids). Or maybe Lucas didn't want to depict violent acts inflicted on a pregnant woman more than he did.
When's the last time you knew someone who passively died of a broken heart? I've known a few people who kinda gave up on things after they lost loved ones. They *kinda* died of broken hearts ... after months of living bad lifestyles and being mildly self-destructive.
Right ... point is: it doesn't happen. And since Padme says she still believes that there is good in Anakin, I find it hard to swallow that she's given up all hope ... including all the hopes associated with raising and protecting her children.
As for Empire Strikes Back DVD stupidity, I've already ranted about how I think the new Palpatine scene totally conflicts with the beginning of the film and the scene is not improved by the release of Revenge of the Sith. But then, I refuse to buy these DVDs, so that scene doesn't exist in my world.