Originally Posted by zinfamous
"that invisible screen that forever separates the audience from the stage."
another part of the definition, found in you wiki link, that you conveniently left out.
Sorry, but I've gone through too many film, literature, and postmodernism classes and seminars to have a cherry-picked definition from wikipedia convince me that the concepts that I have learned over the previous decade have been a gigantic lie.
One must, I think, allow for the possibility that a new generation of audiences perceives the division differently, especially with film. There is no more mystery about the filmmaking process; indeed, by the time high-profile films like TDK reach the screen, much of the audience is aware of the bulk of its content and many details concerning its making.
The fourth wall is not the rigid, immovable structure it once might have been.
I understand your point that immersiveness is the traditional sine qua non
of filmmaking, and that changing aspect ratios, as they serve to repeatedly "take the audiience out of the film," would appear to conflict directly with that necessary characteristic.
But I think it's likely that for many members of today's audience, it's possible to hold in their heads the fact that they're watching a crafted work while still staying within the story. People grow up differently nowadays.
I'm not one of them, and my first reaction was the same as yours. I don't like the changing aspect ratios, because it feels like I'm watching a workprint cut into sections of a finished film.
I simply offer up the possibility that I'm not a member of the audience for which Nolan was crafting the BD version of the movie, and that for the target audience, who have grown up in a world where image borders are always arbitrary and mutable, the issue simply doesn't come up.