Google News has rolled out a "Timeline of articles" so that users can keep track of events as they occur or occurred. Simply click on the link to all articles beneath a cluster of news stories about a news event. You'll see a graph on the right hand side.
I can't help but think of how there seems to be this race to compete in real-time news. Twitter has changed news because you can get real-life witness (and non-journalist) accounts about an event as it happens.
For example, earthquakes are often Tweeted, and recently Google added recent earthquake results to its main search site.
I expect to see more features along this line in Google News and other online news sites as time goes by.