Microsoft just released a new Management Pack for System Center Operation Manager 2005 (formerly MOM) which allows integration with System Center Virtual Machine Manager 2007.
It’s a critical component for large scale deployments and enables monitoring of several Virtual Machine Manager servers, agents deployed on Virtual Server 2005 hosts, and virtual machines stored in available Library Servers.
In no way it replaces the Virtual Server 2005 Management Pack, which instead monitors virtual machines and virtualization hosts running in the infrastructure.
Download it here.