It appears that Office 2003 SP-3 is imminent. Microsoft have just released Download details: Office 2003 Service Pack 3 Administrative Template (ADM), OPAs, and Explain Text Update. From the download page:

The download includes updated Group Policy Administrative Template files, OPA files, and an updated Microsoft Excel workbook that lists the Administrative Template policy settings and OPA settings.

This download includes the following updates:
Policy settings that provide the ability to block file format settings to prevent users from opening or saving specific file types and file formats in Microsoft Office Excel 2003, Microsoft Office PowerPoint 2003, and Microsoft Office Word 2003.
An updated Excel 2003 workbook (Office 2003 Group Policies.xls) that describes policy settings listed in the various Administrative Template and OPA files. It supports changes to the Office 2003 SP3 policy settings. "

The spreadsheet is quite extensive and useful for those who need to control Office UI & functionality.