Not a great analogy. People aren't looking to make "interoperable movies". But let's play that out for a moment. Would a copy of star wars with different actors, different scenic design, different music be much of a salable product? I don't think so.

While I think it would be GREAT to see what Nick Nolte (Lucas was considering him) would have done with Han Solo over the wooden Harrison Ford, I'm not sure I care enough to sit through it all again to find out. Blech.