The announcement of support for Windows 7 and Windows Server 2008 R2 has already been made but here the official KB that describes the update:
KB974722 - Support for Windows Server 2008 R2 and Windows 7 in System Center Operations Manager 2007
This article discusses support for the Windows Server 2008 R2 and Windows 7 operating systems with Microsoft System Center Operations Manager 2007 Service Pack 1 (SP1) and Operations Manager 2007 R2. The information includes management pack availability, known issues, and updates that will be released to address these issues.
J.C. Hornbeck | Manageability Knowledge Engineer