With the advent of 2012 R2 these are significant new features to DFS-R.
If you are used to DFS-R in previous versions of Windows Server you really really need to stop an watch and read the following:
This video is worth a million words
Distributed File System Replication (DFSR) Scalability Enhancements in Windows Server 2012 R2
As part of that video , about 60 minutes in this section explains the new supported limits
DFSR Windows PowerShell
DFS Replication in Windows Server 2012 R2: If You Only Knew the Power of the Dark Shell
If you want to understand the new features in DFS-R replication technology in 2012 R2
DFS Replication in Windows Server 2012 R2: Revenge of the Sync
The new way to set up your First Intital Sync
DFS Replication Initial Sync in Windows Server 2012 R2: Attack of the Clones