Yeah, in some ways I see what Scott is saying. I took my friend Carol to see it and as soon as it was over she says "So was Ennis gay?" I wonder if those people who asked if you were going to be a cowboy now had actually seen it.
I think there is a lot of anecdotal evidence, as Jeff pointed out, of its effect upon the larger world, if mostly among families with gay members, or people who will later face a loved one coming out, they will remember this story.