This was a change that I support. Even as a kid, I wasn't crazy about how Anankin looked. I mean, here you have the badass of badasses with Darth Vader, then when he is unmasked, you have this pasty broken old man. Then, a serene/conservative/fatherly looking guy in the spirit scene. I just always had trouble buying that that guy was Darth Vader.
That said, I was surprised to hear that GL was making that change for the '04 dvd. While I like the change, I also feel that it wasn't absolutely necessary. I could live with the old man being Vader.
The one thing that sticks out now is that fact that he didn't replace Shaw in the unmasking scene with HC. Now that you see HC in the spirit scene, it makes sense to see him as the unmasked Vader. To me, at least. And until that happens, I'll always consider the change as incomplete.
Now, on the other hand, if Lucas were ever to decide to go back and reinsert Shaw, I'd support that move as well.