Google News recently introduced a feature that leverages its exhaustive archives of news as well as priviledged connections to content providers.
Called Google News Timeline, this is a beta version of a tool that could be of tremendous value for researchers looking for coverage of a particular issue over a period of time across a lot of media.
At the moment, there’s not a whole lot of sources to choose from and its largely US centric news outlets that are covered (far less than the thousands covered in the main Google News Portal).
This does show however that Google is interested in and capable of good data visualisation. Given the petabytes of news and information at its disposal, this is one service to keep an eye on. For example, this technology applied to the Peace and Conflict Timeline (a suggestion I made over a year ago to its creators), can easily make the rich information on the site more readily accessible.