Brief description of the Client Security Enterprise Manager:
Forefront Client Security Enterprise Manager provides administrators the ability to manage multiple Client Security deployments from a single server.
After you install Enterprise Manager you are able to centrally manage:
1. Client Security policy deployment.
2. Alerts from Client Security agents in the entire enterprise.
3. Reports from all Client Security deployments in the Enterprise Manager organization.
Not only is it a good idea, it is practically required due to how the MOM 2005 backend scales.

You can read more about the Client Security Enterprise Manager
here.