Mashable notes along with a number of other sources the testing of what's labeled a comments feature for Google News. In a sample Google News query (link will not age well) on a new drug for treating AIDS you can see a comment posted by a doctor specializing in AIDS treatment. Clicking on the comment yields a detailed entry by this person. Mashable indicates that people can submit verifiable emails to Google that relate to a person or entity mentioned in an article to comment on it, though based on this sample query it would appear that it is not just people directly associated with a company or product that can comment. Note also that if you click on a detailed entry you get a number of news stories that relate to the topic covered in this person's comment.
This is obviously not a full-blown comments feature but rather an attempt to draw in original content from experts who can provide insight into topics relating to specific news stories. With the editorial verification and filtering provided by Google it becomes in effect a "letters to the editor" feature for Google News that attaches these expert insights of relatively unlimited length to a wide variety of sources on a topic, giving Google News a unique editorial depth that no one publication will be able to provide.
Most news sites tread on providing user comments very lightly, especially in the aftermath of the failed LA Times' experiment with crowdsourced op-ed pieces and The New York Times' exorcising of user comment boards, but in doing so they threw out the baby with the bath water in many important ways. In the search for increasing user engagement Google has enabled its news users to use its news service as a master source of expert-driven editorial content, even as most news organizations work to reduce unique content from users relating to their own editorial operations. It precludes such experts from having to rely on maintaining their own weblogs or in engaging in the fray of a specific social media service in which their comments may be lost or drowned out all too easily. Kudos to the Google News team for recognizing the opportunity to put news content into perspective with its own unique content - and to pave the way for a new way of looking at how one collects expert insights on both leading and specialized news topics.