Microsoft added a new feature called maintenance mode in VMM 2008 R2. This feature enables users to easily evacuate the VMs from a host in order to perform host maintenance. To integrate this new VMM feature with maintenance mode in System Center Operations Manager; check out the attached MP. This management pack is intended for use with Operations Manager 2007 or Operations Manager 2007 R2 with Virtual Machine Manager 2008 R2, and requires at least the beta version or later or the VMM 2008 R2 management pack.  Copy the text from the attached MP into a text file and save it as MaintenanceModeSample.xml and import it into OpsMgr.