After altering the snippets for Twitter accounts, Google now displays the newest headlines in the snippets for news sites. Search for [washington post], [nytimes], [le monde], [gazzetta dello sport] and you'll find the newest news from the snippets.
Probably the best way to try the new attribute is to search for [news] and check the new snippets.
It's likely that the headlines are obtained from Google News, but not all the sites incorporated in Google News have the new snippets.
