I think I would like to choose whether or not to show the subtitle on the post page on a post by post basis. And having that option would totally negate any need for a byline for us as I'd just put the byline in the content followed by the news story where I could retype the subtitle if I wanted to.
I hope I'm being constructive rather than demanding! And of course if it's not a feature that anyone else wants, it's good as it is :)