Well, the idea is to make sure the article quality be on par with other editorials. This should include critical commentary and comparison of the product or company in question to its competitors. This would be something quite different from those special advertising sections, which almost always feature only its positive aspects.

Since newspapers already publish these articles anyway (without labeling the PR source), the slippery slope is already in action. Although I do agree that money could make things worse for some papers, market mechanisms and transparency could help balance things out.