Last night, Microsoft released SQL Server 2012 RTM Cumulative Update 2, which is Build 11.0.2325.0. It has 37 fixes in the public fix list, which is a pretty high number for a cumulative update. Microsoft maintains a build list for SQL Server 2012 RTM called The SQL Server 2012 builds that were released after SQL Server 2012 was released, which is a good idea to bookmark.
You can find out what build (of any version of SQL Server) that you are running by running this query:
— SQL and OS Version information for current instance
SELECT @@VERSION AS [SQL Server and OS Version Info];
SQL Server 2012 RTM Branch Builds
11.00.1515 CTP3 plus Test Update
11.00.2316 RTM CU1
11.00.2325 RTM CU2