I haven't been following this thread for a while but I have listened to the test CD Zanash was taking about that has both a soundstage depth, and height test.

The depth test has someone speaking in a room and moving away from the microphone. While this does sound like he is further back I think it is only because you hear far more reverb and room interaction as he moves away. He doesn't sound a lot like he is going behind the speakers, only like he was recorded a long way from the microphone.

The height test however is an interesting one! I didn't know what  I was listening to when I first heard it. There is a swishing/clicking sound that is supposed to move up from the speaker. When I didn't know what it was supposed to be doing I thought it sounded like it was phasing differently and somehow sounded nowhere particular in the room. When I did know it was supposed to be going upwards though, it was quite obvious really. It isn't 100% convincing but it does indeed sound liek the noise rises about 5 or 6ft above the speaker! There is then another that arches over from one speaker to the other.

It is obviously a man-made effect though and I would not expect this to occur from normal recording at all. If someone uses the same effect in some studio produced music though, sure Hi-Fi can do a reasonable impersonation of height!

It looks like the disc was made in the early 90's so I don't see why the effect could not be common place now but I haven't heard of many studios using such stuff on normal music. There are indeed special effect plug-ins and units available though.