This has been a hot topic for me recently. This article explains how SharePoint Designer can and should be used in a production environment by explaining Assembly Development vs Artifact Development or "Content" Development.
Team-Based Development in Microsoft Office SharePoint Server 2007
Some key points:
- Content Developers can use SharePoint Designer to create and modify content
- Content Developers have the ability to modify the existing production environment and conduct publication using a content management path to the production Web Farm.
- The authoring environment can exist within the production environment
- From a team perspective, the shared authoring environment is more effective than individually separate authoring environments.
- SharePoint Designer artifacts do not need to be integrated with enterprise source control
- Enterprise source control (such as Team Foundation Server) should be used strictly for assembly development in a team environment, while the effort to integrate content management items into source control is not a supported process.
- Attempts to integrate items into enterprise source control that are considered SharePoint Designer content items and part of a content development require extensive workarounds involving manual processes and procedures.
"For content design and publication, a single authoring environment - in which multiple content developers can use SharePoint Designer to create and publish content - can simplify time spent in migrating content artifacts from separate environments into a production environment.