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:

• Managed Lock Priority: This allows you to manage the priority of table locks acquired by partition SWITCH and Online Index Rebuild (OIR), thereby allowing you to mitigate any negative performance impact of these locks on the primary workload on the server.
• Single Partition Online Index Rebuild – This features allows you to rebuild indexes online for individual partitions, thereby increasing application uptime.  This is great for large partition tables.

More Info:

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