When we think of Darth Vader, we conjure up images of a tragic and fallen hero turned to the dark side, stoic, violent, angry and alone. Well, that's how we used to see him, anyway.
Was it the lackluster prequels that changed our minds? Nope. It's Vader's one-man show at an old folks home that turned our frowns upside down.
See for yourself.
What put the pep back in the man's step? Maybe someone finally fixed that faulty iron lung of his. How else do you explain his newfound trombone skills?
In any event, if Lucas wants to keep making alterations to the original trilogy, we can think of far worse ideas than rewriting Vader as a song-and-dance man. It's certainly no less plausible than Han Solo shooting second.