[...] record where the audio is supposed to come from, instead of which speaker it should be played on. This way a movie would never need its audio remastered again, because the fact that the plane coming in at 2 O'Clock wouldn't change no matter how many speakers you had, it wouldn't even matter if you had a speaker placed precisely at 2 O'Clock. So basically your AVR [audio/video receiver] would render the audio on the fly based on the number of speakers, and where you placed those speakers by using the recorded sounds and the data about those sounds.
Future-proofing surround sound
Home theater surround sound is currently transitioning from 7.1 to 9.1 which has the drawback of needing to re-encode all 7.1 content. The following idea would make audio content independent of the number of speakers: