Extended Supports entails:
- Paid support
- Security update support at no additional cost
- Non-security related hotfix support requires a separate Extended Hotfix Support Agreement to be purchased (per-fix fees also apply
Support for Windows Server 2003 Service Pack 1 also ended today. If you have not upgraded to Service Pack 2 for Windows 2003, then you are totally unsupported.
All editions of Windows Server 2003 and Windows Server 2003 R2 will transition from the Mainstream Support phase to the Extended Support phase on July 13, 2010.
For a complete breakdown of the support phases, see the Support Lifecycle Page