With modern multichannel discs, the remix can put the sound stage around you. It all depends on the one doing the remix, how he wants the soundtrack to present. A recent article in S&V showed how Telarc microphoned a concert theater for a classical presentation that, in the original work, wrote in a singer in the balcony behind. The possibilites are endless depending on the producer.
However, the traditional soundstage, like a theater, puts the main action at the front. The surrounds and rear surrounds put the ambience around you. TV and DVD dialogue must appear to come from the speaker on the screen, hence why the center channel is place above or below. Voices or sounds off center stage go left or right. I was quite happy with the soundstage of my Technics 5.1 until I replace it with the Denon 2805 and two rear surrounds. I played my first DD 7.1 (The Incredibles) last week. Now that's a sound stage!