Microsoft have recently published a whitepaper that captures the results of bandwidth optimization experiments conducted in the Microsoft® Engineering Excellence Center (EEC) lab by using the Riverbed Steelhead appliance WAN optimization devices with Windows Server 2012 Hyper-V Replica.
Windows Server 2012 Hyper-V Replica allows asynchronous replication of Virtual Machines across Wide Area Networks. By utilizing a WAN optimization appliance, like the Riverbed Steelhead, you can improve your overall replication strategy and provide bandwidth effective WAN efficiencies. The de-duplication of the devices abilities is certainly something that provided very interesting results, which I highly recommend reviewing.
You can download the whitepaper here.