Dynamic Access Control in Windows Server 2012 is a new file-system authorization tool that simplifies the management of access and auditing by providing Windows administrators with centralized control at the domain level. Dynamic Access Control enables manual and automatic classification of files as well as centralized file access and audit policies to control and audit who can access data on your file servers.
Int his video TechEd 2012 speaker and author Mark Minasi talks about why Dynamic Access Control is his number 1 feature in Windows Server 2012.