Hi G,
Unfortunately your right , sql 2012 isn't supported as of yet as per pg 15 of the installation guide (http://www.vmware.com/pdf/vcenter-configuration-manager-56-installation-guide.pdf):
Namely:
"VCM supports Standard and Enterprise editions of SQL Server 2008 R2." Could try it with 2012 but indeed could run into a problem down the line that you might need VMware support assistance with. Hope this helps