Apple @ Work: How to handle migrations to new Macs in the event of damage

One of the challenges with moving away from traditional Active Directory networking environments is handling device migration and restoration in a damaged Mac. How do enterprise Apple environments address this in a way that scales to thousands of devices? In Active Directory environments, IT administrators just needed to deploy a new PC, join the Domain, and then the employee is back up and running. In a situation where Macs are not bound to a domain, how do IT departments handle Mac backups in