WSUS and Active Directory
The Microsoft Solution for Hosted Messaging and Collaboration recommends that you use Active Directory Group Policy objects (GPOs) to centrally manage and control how updates are applied to the servers in your data center.
Without Active Directory, you will need to manipulate Automatic Updates settings and registry settings on each server manually or through server scripting. In larger data centers, these manual procedures can significantly increase the time it takes to distribute critical updates, which can expose your organization to increased risk. You should determine if you will use Active Directory before you formulate your update management strategy.
For more information on Active Directory, see Centralized Management.