To use the vSphere Replication component of SRM, are there any licensing issues? I know if you use the standalone version that ships with vSphere 5.1 & 5.5 you can replicate an unlimited number of VM's (up to the 1,000 VM limit) without additional licenses provided you have a Standard, Enterprise or Enterprise Plus license.
To use SRM with VR (or even with ABR) you will need SRM licenses, and maybe additional vCenter Server licenses, if you not already have two vCenter Servers.
SRM licenses can be ordered by per-VM (available in Standard and Enterprise Edition) or per processor as part of vCloud Suite Enterprise.
Regarding SRM licensing, you can also check this post: Additional software / license for running SRM ?