Google News has been reviewing it's inclusion criteria for websites listed as sources. Already the search king has dropped a number of websites from it's online news listings. The exact number of websites has not been released. The overt concern here has been a marked increased in spam and low-quality sites. At times, these spammy sites have even appeared quite prominently within the Google News listings.
Negative press such as the CNET article on how some websites haved "gamed" the system to achieve prominence within Google News and the more recent DecorMyEyes have caused Google to further refine it's listing standards. At times, an example being the DecorMyEyes, Google will go in an "manually" demote a site that it views as spammy or low quality. "We periodically review news sources, particularly following user complaints, to ensure Google News offers a high quality experience for our users" (Source: The Google News Team). Google also provides content, design and technical guidelines for web designers and publishers to help provide a measure of transparency to the process. ( Page: https://www.google.com/support/webmasters/bin/answer.py?answer=35769#3.)