What’s New in Active Directory Domain Services in Windows Server 2012 (TechNet)
The four tenets of the Windows Server 2012 AD DS improvements:
“Virtualization that just works
Providing greater support for the capabilities of public and private clouds through virtualization-safe technologies and the rapid deployment of virtual domain controllers through cloning.
Simplifying the on-premises AD DS deployment (formerly DCpromo) with a new streamlined domain controller promotion wizard that is integrated with Server Manager and built on Windows PowerShell.
Integrating claims-based authorization decisions into AD DS and the Windows platform that permit a combination of centralized access policies, directory attributes, the Windows file-classification engine, and compound-identities comprising both user and machine identity
Providing a consistent graphical and scripted management experience that allows you to perform tasks in the Active Directory Administrative Center that automatically generate the syntax that is required to enable automation for the task in Windows PowerShell.
AD DS Platform Changes
Updating the AD DS platform with changes such as relative ID improvements, deferred index creation, and off-premises domain join improvements.”
More detail on TechNet: