Either I've scooped everyone on this or I just can't find any documentation of this as a prior Google feature. Google now includes a "Description" field in a search result listing for any page that has a listing in the Open Directory. See this example. It's a nice addition as it provides the user a nice short description of a page. The way they do this also makes sense since there's an editorial process for those descriptions in the Open Directory whereas description meta tags are often used to mislead search engines.