Not just movie/music studios. Who could reap huge rewards from great distributed version control? Anyone who collaborates on some computer file regularly.
So everyone. Or at least everyone who works in an office.
My own erstwhile field of small business accounting is all about version control. An enormous amount of energy goes into keeping tabs on which file is most current and ensuring that work isn't done in a non-current file.
Same thing for anyone who regularly collaborates on documents or spreadsheets or images: lawyers, advertisers, my friend the outdoor school counselor, journalists, etc.
The state of the art here isn't very good. For all the products out there, I'd guess 90% of actual version control happens via emails. Case in point:
A journalist friend of mine is currently attempting a small intra-office coup to switch from Email/Excel to Asana for scheduling and managing the editing process. It is not going well. Email/Excel will probably win.
But the old people won't be around forever. The opportunities to improve on the state of the art are vast. The amount of energy people spend on keeping current could be dramatically reduced.
Github has plenty of potential.