We expect that System Center 2012 R2 Orchestrator RTM will be available at the end of this week.
Some want to begin to prepare the systems to install System Center 2012 (R2) Orchestrator and perhaps wondering about an appropriate environment to start.
The architecture of Orchestrator is described here: http://technet.microsoft.com/en-us/library/hh420377.aspx.
Runbook Server(s): The Runbook Servers execute the Runbooks. They have a direct connection to the database.
You can have more than one Runbook Server. Choose at least two to benefit of the built-in failover mode.
Management Server: The Management Server connect the Runbook Designer to the Datastore. The Management Server does not need to run for the Runbook Server(s) to execute the Runbooks. With installing the Management Server the Service "Orchestrator Runbook Server Monitor" is installed automatically. This is one reason that it is not recommended to have more than one Management Server running for one Orchestrator instance.
Web Services: The Web Services provide the Orchestration Console which allows to control the Rubooks (status, start, and stop). To have control even if a Management Server is down it's recommended to install the Web Services on a separate system as the Management Server.
Database: The Orchestrator Database is the central component from Orchestrator. It's recommended to have the database on as SQL-cluster-instance.
Recommendation to start: I recommend to start with two Systems. One with Runbook Server and Management Server and one with Runbook Server and Web Service.
Of course, if you have also to consider some company policies of security and firewalls there can also be other setups.