As mentioned in here the  System Center Server Management Suite Enterprise Licensing has changed since today. Microsoft has developed a transition path from the SCSMSE to the newly SMSD: License Grant: One-time License Grant of System Center Server Management Suite Datacenter (SMSD) to License Holders of System Center Server Management Suite Enterprise (SMSE): As a one-time exception in connection with the transition of SMSE* from a suite that allows for the management of any number of OSEs...(read more)

Read the complete post at http://scug.be/blogs/scom/archive/2009/07/01/system-center-server-management-suite-enterprise-transition-to-system-management-suite-datacenter.aspx