Locked video, versioned audio

Originally posted by Tim, with 14 votes at time of migration.

Working in audio post-production for Film & TV -- we have a 'picture locked' video reference file that does NOT change. 
What does change is the audio. It would be extremely useful to be able to upload/version the audio tracks separately, since they're the only assets changing.
Would provide storage space savings too -- my audio files for a ~30 min video are ~500MB. The package with video is 3+ GB.
Do note that this is for audio tracks that span the entire length of the a/v asset -- NOT, say, "here's a standalone music bed that should kick in at timecode 01:28:24;10."
I hope I've been clear. Thanks very much -- this is a great new product.