Microsoft just released Service Pack 1 (SP1) for Windows Server 2003. This new update is more the just patches, it includes several security feature enhancements to help you make Windows Server 2003, faster, more secure and reliable.
Some of the new features are a new firewall and a security configuration wizard which gathers information about specific server
roles and automatically blocks all services and ports not
needed for those roles. Another new feature is the 'post-setup' which blocks all inbound connections to the server after
installation until the latest security updates have been delivered
via Windows Updates.
Note: If you have Automatic Updates enabled on your server, SP1 will automatically be downloaded through this service as a 'High Priority' update in July 2005.