Multiple point-in-time replicas
Previous versions of vSphere Replication kept only the most recent copy of a virtual machine. Version 5.5 can keep up to 24 historical snapshots. You could retain one replica per day for 24 days, or one per hour for 24 hours -- however you want to slice it. Recovery always draws on the most recent copy, but from there, you can use the snapshot manager to revert to any other point in time.