That's actually a pretty good theory HG! It may not have been at the top of Joss' thoughts but it very well could have been bleeding through from his subconcious.

From Gaffer Tape:

I'm now not sure if I want to see anymore Firefly material because I just don't see how it will be as good without... well, you know.

Actually my thought was that you could do a couple of 'fill-in' movie/specials... focusing on what happened between the end of Firefly and the start of Serenity. That way ALL the cast could be there just as they were originally and other characters' stories could be focused on.

Speaking of- I think I've mentioned this elsewhere but I'd like to know what various people here think: From watching Firefly *first* before the film, I perceived the show to be mainly about Mal- about what led him to be where he is and about how his convictions and his new 'family' would help him find his place in the universe (though he may not have known he was looking for it). I saw River's story as being important, but just one of the tales of the extended family and essentially a plot device that would lead to a season's worth of stories.
A friend who watched and loved 'Serenity' but never saw Firefly perceived the overall story as being about River, and Mal and the rest were just devices needed to tell River's tale. This would again cast Mal in a 'Han Solo' type supporting role to River's 'Luke Skywalker'.

So my question is- if the series had lasted, whose story do you think it would have been?