Hyper-V virtualisation is one of the key benefits of Windows Server 2012, and it works essentially identically in R2 to the original version. One important exception to bear in mind? You shouldn’t use R2’s shared virtual hard disk feature to hosting virtual machine operating systems — purely for shared data sotres.
Microsoft Hyper-V guru Roger Osborne makes that point in an update to his guide to best practices for Hyper-V:
Do not use a shared VHDx file for the operating system disk. Servers should have a unique VHDx (for the OS) that only they can access. Shared Virtual Hard Disks are better used as data disks and for the disk witness.
If you haven’t tried out Windows Server 2012 R2 yet, right now might be a good time, given you can potentially win an Xbox One).