The KB http://support.microsoft.com/kb/949389 discusses the list of issues fixed in System Center Essentials Service Pack 1 (Released today!!).
The list below includes specific SCE KB articles and Operations Manager 2007 issues which affect SCE fixed in SP1.
This article contains a list of Microsoft Knowledge Base articles that describe the issues that are fixed in System Center Essentials 2007 Service Pack 1 (SP1). This article is primarily intended to help IT professionals and corporate Helpdesk workers to support and to maintain a company’s computer system.
943111 (http://support.microsoft.com/kb/943111/) Description of System Center Essentials 2007 post-release hotfix rollup
936339 (http://support.microsoft.com/kb/936339/) Windows-based computers are not displayed in the Network Topology diagram view in System Center Essentials 2007, and WSUS component parts fail on the Essentials 2007 agents after you deploy the agents
937831 (http://support.microsoft.com/kb/937831/) The installation of System Center Essentials 2007 fails during the Reporting part of Setup and the following information is logged: "The specified domain does not exist or cannot be contacted"
938509 (http://support.microsoft.com/kb/938509/) You cannot approve pending actions for servers in the "Agent License Limit Exceeded" state even after you add more server licenses in System Center Essentials 2007
937470 (http://support.microsoft.com/kb/937470/) A notification subscription's Alert Criteria options do not work as expected in System Center Operations Manager 2007
935896 (http://support.microsoft.com/kb/935896/) When the Health Service (HealthService.exe) runs timed scripts in System Center Operations Manager 2007, high memory usage may occur
936838 (http://support.microsoft.com/kb/936838/) After a System Center Operations Manager 2007 agent sends discovery data to a management group, no rules are deployed for monitoring in later management groups
939799 (http://support.microsoft.com/kb/939799/) The System Center Operations Manager 2007 agent is unable to restart the health service after its monitored thresholds are exceeded
936481 (http://support.microsoft.com/kb/936481/) You cannot install the System Center Operations Manager 2007 Reporting feature in a disjointed namespace environment
938505 (http://support.microsoft.com/kb/938505/) Some report information does not appear in Japanese in the Japanese version of System Center Operations Manager 2007
939364 (http://support.microsoft.com/kb/939364/) System Center Operations Manager 2007 cannot find some network devices by using the network device discovery process
939585 (http://support.microsoft.com/kb/939585/) Some SSL Monitoring monitors display an incorrect status or an incorrect name in System Center Operations Manager 2007
936219 (http://support.microsoft.com/kb/936219/) Error message when you try to install System Center Operations Manager 2007 Reporting: "The wizard was interrupted before Operations Manager 2007 could be installed"
937467 (http://support.microsoft.com/kb/937467/) Updates cannot be distributed to managed hosts, or you cannot import updates directly from partners when you import updates from partner catalogs in System Center Essentials 2007
938989 (http://support.microsoft.com/kb/938989/) Subscription notification objects in System Center Operations Manager 2007 may not be displayed correctly on a computer that uses a regional setting other than "English (United States)"
938993 (http://support.microsoft.com/kb/938993/) You cannot deploy an agent by using the Discovery and Installation Wizard in System Center Operations Manager 2007
938991 (http://support.microsoft.com/kb/938991/) The SQL Server 2000 database engine health is not monitored in System Center Operations Manager 2007
938988 (http://support.microsoft.com/kb/938988/) You may be unable to delete a log file on a client computer in System Center Operations Manager 2007
943706 (http://support.microsoft.com/kb/943706/) The MonitoringHost.exe process on the System Center Operations Manager 2007 root management server may consume more than 2 gigabytes of memory
941985 (http://support.microsoft.com/kb/941985/) A management group that contains an Exchange Server computer may intermittently stop receiving new alerts in Microsoft System Center Operations Manager 2007
938507 (http://support.microsoft.com/kb/938507/) Report scheduling fails in System Center Operations Manager 2007 when the regional settings on the client computer differ from the regional settings on the server
938510 (http://support.microsoft.com/kb/938510/) You cannot obtain elevated user rights in management servers and in agents in System Center Operations Manager 2007 or System Center Essentials 2007 environments
939606 (http://support.microsoft.com/kb/939606/) Agent approval problems may occur when you run System Center Essentials 2007 in Service Provider mode
940224 (http://support.microsoft.com/kb/940224/) The Optimized Performance Counter Collection rule collects multiple values of 0 (zero) in System Center Operations Manager 2007
941307 (http://support.microsoft.com/kb/941307/) A health monitor may display state changes in an incorrect order in System Center Operations Manager 2007
941943 (http://support.microsoft.com/kb/941943/) The HealthServiceStore.edb file size grows to several gigabytes over time in an agent that is running System Center Operations Manager 2007
942168 (http://support.microsoft.com/kb/942168/) The Health service does not start after you install the RemotelyAnywhere program on the Root Management Server in System Center Operations Manager 2007
946429 (http://support.microsoft.com/kb/946429/) Error message when you try to view the AD Domains topology view in System Center Operations Manager 2007
946431 (http://support.microsoft.com/kb/946431/) You do not see the additional alert criteria that you selected when you view the properties of a subscription in Microsoft System Center Operations Manager 2007
945946 (http://support.microsoft.com/kb/945946/) Event ID 2115 is logged, and a management server generates an "unable to write data to the Data Warehouse" alert in System Center Operations Manager 2007
943211 (http://support.microsoft.com/kb/943211/) You cannot use Active Directory integration for untrusted domains in System Center Operations Manager 2007
941977 (http://support.microsoft.com/kb/941977/) You receive error messages when you try to edit the Web application monitoring settings in System Center Operations Manager 2007