Not normally a part of the Patch Tuesday cycle, Microsoft has opted to deliver the 2nd service pack for SQL Server 2012 amid the stack of today’s updates.
As most of you know, Microsoft uses service packs to provide updates, fixes, and enhancements to products. Between service packs the company utilizes hotfixes and update rollups to bridge the gap between major product updates. A service pack is considered a major product update and should be reviewed for gotchas and special requirements before updating. If at all possible, the service pack should be rolled out in a test environment first before delivering to the production environment. This is an example where an Azure VM would make a good testing environment should local resources be unavailable.
The service pack download is located here: Microsoft SQL Server 2012 Service Pack 2 (SP2)
Other important links: