The Nieman Lab just released an amazing new media research tool called Media Cloud. The impetus behind the project and some of the basic features are covered in this excellent interview with Ethan Zuckerman (who uses DailyKos coverage in several examples).
The new tools access a collection of data streams from msm news and the blogosphere. They allow researchers to view topic spread and word associations visually with word clouds, charts and a world map demonstrating coverage by source. They have thousands of streams.
The site is just launching today (so the access is a bit wobbly), but over the long term, the creators see the Media Cloud as an open access media research tool. According to Zuckerman, they will eventually be adding an API to let people really get to work quantitatively analyzing the breadth of world (english-language) coverage.