2012에서 2012 R2로 가는 라이센스 비용은 없는 것으로 알고 있는데,

hyper-v가 안되던 (별도의 hyper-v서버를 설치해야 했던) 에션셜에 기본으로 hyper-v가 되는 것 같습니다.

standard에 비해서 hyper-v 기능은 큰 차이가 없는 것 같은데, 어떤지 알고 싶습니다.

http://blogs.technet.com/b/sbs/archive/2013/09/03/understanding-licensing-for-windows-server-2012-r2-essentials-and-the-windows-server-essentials-experience-role.aspx

The Hyper-V role and Hyper-V Manager console are now included with Windows Server 2012 R2 Essentials! The server licensing rights have been expanded, allowing you to install an instance of Essentials on your physical server to run the Hyper-V role (with none of the other roles and features of the Essentials Experience installed), and a second instance of Essentials as a virtual machine (VM) on that same server with all the Essentials Experience roles and features. Previous versions of Windows Server Essentials (and Windows Small Business Server before that), made it necessary to obtain a hypervisor separately, such as the Microsoft Hyper-V Server, but that is no longer required. In addition, we are working with our OEM partners to help them offer server hardware pre-installed and pre-configured with Windows Server 2012 R2 Essentials running as a virtual machine.