well...most people cannot tell the difference when WATCHING a movie. I am convinced of this after actually testing (double blind) here at home with friends, neighbours, etc. It has been fun doing this. So I asked a colleague's daughter who is in nursing about this. She asked one of her profs who said he was not surprised. The human mind ignores most audio (not all, but most) in a highly visual task, such as watching a movie. Or even driving a car...ever had a close call when someone talking to you when driving and you forget what they said because you were almost in an accident. The same happens in a movie. Now...this is not to say that high resolution audio is bad...it is just a waste of space and a way to sell movies. Now with the same people, if you turn the TV off and have them CONCENTRATE on the audio, yes most people can tell a difference; just not with all the video at the same time. I am convinced of this, so I always reencode to mkv 448 AC3 for my media server.
This is like DVD-A...awesome sound, I love that high resolution audio, but I am only listening to it, not watching it.
So I think high resolution audio is a red herring to sell blu ray....it is just not needed for the average person..of course, your millage will vary!!!