In case you missed the announcement, you can now deploy SCOM 2012 R2 and use SQL 2014 as your database server platform.
We made some additions to supported SQL versions for System Center. This includes adding support recently for SQL 2014, along with now officially supports SQL Server 2008R2 Service Pack 3 for OperationsManager 2012 R2.
Check out the latest table here:
The product group announcement and caveats are here: http://blogs.technet.com/b/momteam/archive/2015/02/23/opsmgr-2012-r2-now-offers-additional-support-for-sql-server.aspx