A couple of weeks ago I posted about the new features coming in windows 2012 R2. One of those features was Dada Deduplication for virtual machines.
There are now two great blogs on the Microsoft website explaining how data Deduplication is going to work on VDI.
The first blog is Deploying Data Deduplication for VDI storage in Windows Server 2012 R2
and the second blog is Extending Data Deduplication to new workloads in Windows Server 2012 R2
Also note that it is clearly stated that although it will work on all Hyper-V loads it is only officially supported for VDI.