One of the ways you can create and edit a custom Document Information Panel is by starting from the Microsoft Office SharePoint Server 2007 user interface. You choose the content type for which to create or edit a custom Document Information Panel. Office SharePoint Server 2007 starts Microsoft Office InfoPath 2007 and supplies the content type schema as the primary data source, and the automatically generated form as a starting point. After you edit the form, you publish it directly to the content type or to another location. This Office Visual How To shows how to create and edit a custom Document Information Panel from SharePoint Server 2007.
I’ve been considering this route — in combination with a script to automatically display the panel at Blog.docx onload, and embedded controls — to grow SharePoint blogs into full-featured announcement applications that can capture real data to lists and still provide the end-user familiarity and convenience of Word. Anyone played with this concept?