Microsoft has just released Windows Server 2003 R2, here's a short snip from a Q&A posted on their website:
Today Microsoft announced that Microsoft Windows Server 2003 R2, an update release of the Windows Server 2003 operating system, has reached general availability. The company also announced enhancements to other products, initiatives and technologies that integrate with Windows Server 2003, including Service Pack 2 for Microsoft Internet Security and Acceleration (ISA) Server, all of which are designed to create a better and more secure server offering for midsize businesses, customers with branch office operations and those with robust storage needs.
Based on Windows Server 2003 with Service Pack 1, Windows Server 2003 R2 delivers new capabilities and value for customers, including a more efficient way to manage and control access to local and remote resources, while easily integrating into existing Windows Server 2003 environments. The R2 release also provides a scalable, security-enhanced Web platform, simplified branch server management, improved identity and access management, and more efficient storage management.