DVD movies with the highest bitrates?

I recently discovered Superbit DVD’s and it got me interested in what DVD movies have the absolute highest bitrate. 9.8 mbps is supposedly the highest bitrate DVD players can read without problems, at least from what I see online. What movies the push 9.8 or close to it?

Are Superbit the highest bitrates of any DVD’s? Or do some modern DVD’s have bitrates just as high as Superbit? What exactly makes these types of DVD’s so special and why didn’t other companies take advantage of higher bitrates before Sony did?