as you have probably seen, there is no new KMS MP for KMS 2012 and SCOM 2012. The old one is only for KMS 2008 monitoring and SCOM 2007. Since SCOM 2012 can read 2007 MP schemas, the MP can be used also with SCOM 2012.
However the discovery will take place only when detecting some KMS keys which are 2008 specific.
To work around this issue you can create on the KMS 2012 server a registry key under the following path: SOFTWARE\Microsoft\Windows NT\CurrentVersion\SL
Create a new key named: KeyManagementServiceVersion
It does not need a specific value, we only detect its presence.
This is a workaround for monitoring KMS 2012 servers with SCOM 2012 with using also the official MP.