The Google News Blog announced they have updated their news quality guidelines to make it crystal clear that if you violate their guidelines they can boot you out of the Google News index.
Google wants you to know that since Google News is not a marketing driven service, you using it to sell stories is against their guidelines. Google said "Google News is not a marketing service, and we consider articles that employ these types of promotional tactics to be in violation of our quality guidelines."
Specifically, news sites that mix news content with affiliate, promotional, advertorial, or marketing materials for your company or another party goes against Google's guidelines. If you do that, block the articles from being indexed or included in Google News.