vRanger works with well with three main De-Dup vendors and we have thousands of customers that use these de-dup devices to replication their vRanger backups to a remote site. Because of the nature of De-Dup on image based backups, there are major benefits to doing this 1.) On the amount of data sent over the WAN and 2.) The time to takes to get the data to the remote site. Of course you can also just use a pair of NAS devices that can replication between each other over the WAN, to get your vRanger backups to your remote site. Here is a blog on replicating backup images.
Also, here are the three major vendors that vRanger works with.
DataDomain - http://www.datadomain.com/
ExaGrid - http://www.exagrid.com/
Quantum - http://www.quantum.com/technologies/deduplicationreplication/index.aspx