Microsoft licensing for vReplicator replicas
When using vReplicator to replicate a Windows virtual server from one site to another, you don’t need Microsoft licensing for the target, as it is a powered off image.
Microsoft clarify this here (emphasis mine):
First, we are licensing by running instance, which is to say the number of images, installations and/or copies of the original software stored on a local or storage network. Instead of licensing every inactive or stored virtual instance of a Windows Server System product, customers can now create and store an unlimited number of instances, including those for back-up and recovery, and only pay for the maximum number of running instances at any given time.