The speed of online publishing often makes the delay required to manually art direct a story’s presentation unacceptable. And with so many devices mandating so many different presentations, the expense involved is huge. So manual art direction isn’t feasible, and the problem is getting worse.
The only option in my mind is to replace manual art direction with rule-based art direction. These rules, though imperfect, would be designed to do the same thing a human art director does: clarify or enhance a story’s meaning by providing context for it and making its presentation visually appropriate. For example, we might have rules like: “When an article is satire, use Typeface X.” or “When an article includes key people whom the reader might not know, offer background information on those people in a tooltip.”
Metadata comes in because it’s what enables the computer to apply these rules automatically; if the computer doesn't know what topics the content is about, how important it is, who it’s talking about, etc. then it can’t customize the presentation accordingly. So structured content + rules is the replacement for traditional art direction.
And this is beginning to happen (more). The Guardian’s iPad app is a recent example: each story is assigned an importance score that dictates how prominently it will be displayed.