The Windows Server 2003 Service Pack 1 Release Candidate is now available. Here's a link to the WIndows Server System page for the release candidate:
Windows Server 2003 Service Pack 1 Release Candidate
On this page you'll find information for Windows Server 2003 Service Pack 1 (SP1) Release Candidate (RC). This version of the software is intended only for installation in a test environment. We advise against installing and evaluating beta software on any production computers.
And this is a link to the page in the download center:
Microsoft Windows Server 2003 Service Pack 1 Release Candidate (32-bit)
Install Microsoft Windows Server 2003 Service Pack 1 (SP1) Release Candidate (RC) to help secure your server and to better defend against hackers. Windows Server 2003 SP1 RC enhances security infrastructure by providing new security tools such as Security Configuration Wizard, which helps secure your server for role-based operations, improves defense-in-depth with Data Execution Protection, and provides a safe and secure first-boot scenario with Post-setup Security Update Wizard. Windows Server 2003 SP1 RC assists IT professionals in securing their server infrastructure and provides enhanced manageability and control for Windows Server 2003 users.