Microsoft Knowledge Base Article 891861 contains the following summary and introduction:
This article announces Update Rollup 1 for Windows 2000 SP4. The update rollup will be released in mid-2005.
It will contain all the security-related updates that have been produced for Microsoft Windows 2000 between
the time when Windows 2000 Service Pack 4 (SP4) was released and the time when Microsoft finalizes the contents
of the update rollup. Additionally, the update rollup will contain some important non-security updates.
This article contains information about the update rollup and lists some answers to frequently asked questions about the update rollup.
This article contains information about Update Rollup 1 for Windows 2000 SP4 and lists some answers to frequently asked questions about
Update Rollup 1 for Windows 2000 SP4. To make it as easy as possible for customers to help maintain the security and stability of their
Windows 2000-based computers, Microsoft will produce an update rollup for Windows 2000 with SP4. The update rollup is planned to be released
in the middle of 2005.