I often tell my clients that every website needs a "product manager." This is the person who ensures that the website is meeting the needs of the customers (the audience). A product manager understands the customer and prioritizes the enhancements of the technical platform as well as the production and maintenance of the content. The product manager may not have deep technical experience in software architecture, information architecture, writing, or graphic design but needs to bring these disciplines together to create a product that is useful.
I have recently come across two very good articles on product management. The first is Program Manager by Joel Spolsky. He calls the role a "program manager" and narrowly focuses on the discipline of software development. His program manager leads a small team of developers to build an application (or a subset of a large application) by writing a functional specification that defines the product's vision and behavior. The article nicely describes how the product manager communicates with and manages a technical staff.
The second article is Internal CMS Product Management by David Hobbs. In his article, David focuses on the web content management system as the product and the users of that system as the customers. This role is particularly visible during the initial CMS implementation but is important throughout the system's lifetime to keep it relevant and useful. Requirements always change — not just when the business changes but also when it learns and learning is inevitable with a disruption like a new CMS that may streamline processes and create opportunities. People change too and they may need different training and/or encouragement as their responsibilities change. Too many content management systems fail from post deployment neglect. Always budget for continuing maintenance and enhancement of the system. Practicing the advice in Hobbs's article will help you avoid those pitfalls.
But, as I mentioned earlier, I think that the real product is the web site itself — not the content management system. A great CMS is worthless with bad content. We manage content because it is (or should be) valuable to an audience. A CMS doesn't make good content, people make good content. The best a CMS can do is eliminate some of the barriers that prevent users from making good content. There are plenty of other barriers that the CMS can't eliminate: no time, no interest, no incentives, no skills, etc. The product manager needs to address these as well.
I don't think that I am asking too much for a product manager to guide the technology and help content producers create good, well organized content. Wikis are a good example to look to. Wikis that continue to be successful after their novelty wears off usually have an evangelist that is constantly tracking content updates and giving feedback to authors (Is this page redundant? Does the title make sense? Is the information still accurate? Is it findable?). When you really think about it, this is the role of an editor in a media and publishing company. Maybe all companies that manage content (even for internal purposes) should think of themselves as publishers and have editors that push their contributors to produce a worthy product.