Back in WordPress 3.1, a new feature called Post Formats was added to enable theme developers to more easily denote different types of posts in order to make “tumblog” themes. But the feature is lacking as it stands today. The UI is simply not as nice as services like Tumblr, and there isn’t really a set of prescribed standards for how to use Post Formats. So some themes store link URLs in Custom Fields, while others grab the first URL out of the post body. That sort of inconsistency makes portability between themes a nightmare.
Alex King and his company Crowd Favorite have a proposed solution. Their plugin adds a really nice UI to the New Post screen, with tabs that appear depending on which Post Formats your theme enables and different input fields that change depending on which tab is selected.
In addition to the way cool plugin, they have a sensible naming convention for custom fields to go along with it. I think it would great if the Core team adopted that as a recommendation for theme developers, and incorporated the UI plugin into WordPress proper.
Alex King did say, back in November, that he planned to suggest it to the Core developers once WordPress 3.3 shipped, so keep your fingers crossed.
WordPress Post Formats Admin UI [Alex King]