SMS2003 gets a new name ...
Lifted from the SMS Server homepage:
Announcing System Center Configuration Manager 2007
The official name for the next version of Systems Management Server (SMS) 2003, codenamed "SMS V4," was announced at the Microsoft Management Summit 2006. With the release of the next version, SMS will officially join the Microsoft System Center family of products and be known as System Center Configuration Manager 2007.
You can preview SCCM (SMS V4) here