SQL Server 2014 has enhancements to two common database maintenance operations:Partition Switching and Online Index Rebuild. This will greatly increase enterprise application availability by reducing maintenance downtime impact.
The two new features are:
Exploring Partition-Level Online Index Operations in SQL Server 2014 CTP1
Improved Application Availability During Online Operations in SQL Server 2014
Exploring Low Priority Lock Wait Options in SQL Server 2014 CTP1