Microsoft has recently announced that from 1st September 2013 the SQL Server 2012 Runtime for licensing will be available to purchase.
Existing customers who are on a current maintenance plan and with SQL Server 2008R2 Runtime on their accounts will be entitled to receive SQL Server 2012 Runtime as an upgrade:-
Customers with SQL Server 2008R2 Standard Edition Runtime will be automatically upgraded to SQL Server 2012 Standard Edition Runtime.
Customers with SQL Server 2008R2 Enterprise Edition Runtime will be upgraded to SQL Server 2012 Enterprise Edition Runtime upon request. This process will give you the opportunity to license additional SQL Server 2008R2 Enterprise Edition Runtime Servers and CALs prior to the upgrade.
From September, Microsoft will also be increasing the price of SQL Server Standard Edition Runtime CALs to £132.00. The price of SQL Server Standard Edition Runtime Servers and the price of SQL Server 2008R2 Enterprise Edition Runtime Use Servers and CALs will remain unchanged.
Customers with SQL Server 2008R2 Enterprise Edition Runtime will not be able to license additional Servers and CALs from the Dynamics pricelist once they upgrade to SQL Server 2012 Enterprise Edition Runtime.