Actually, 7.1 as it is on BDs makes more sense for homes. Movie theaters, because they are so large, don't really have a place for "rear" speakers that would be well suited for all audience members. They use an array of surround speakers, which are located on the left and right walls. The longer the seating area the more speakers they'll use. For rear speakers they'll pretty much have to mount them on the front wall of the projection booth. That's pretty far away from people sitting in the front row. The array of surround speakers, can provide a rear-phantom effect pretty well, because there is usually another set of surrounds somewhere behind your seating position.
Some theaters are already running 7 discrete channels, but they are left, left-center, center, right-center, right, surround-left, and surround-right. That makes more sense because the screen is so large.
Seems, that home theater owners are not the only ones being milked for money.
