Anyone currently running Oracle Standard Edition, or Standard Edition One needs to be aware of the licence changes brought in with 12c (Oracle 220.127.116.11 Standard Edition 2).
Oracle has replaced SE and SE One with SE2 and has introduced new socket and CPU thread restrictions, meaning that a current SE customer may need to make the big licence step up to Enterprise Edition (EE) to remain compliant.
This looks like a not-too-subtle push for smaller customers to embrace the Oracle Database Cloud. Could it push smaller customers away from 12c altogether ? Possibly, but Oracle seems to find that it is a risk worth taking.
Here is a link to the Oracle SE2 doc:http://www.oracle.com/us/products/database/oracle-db-se2-brief-2680836.pdf
Note to Oracle SE customers running on a VMWare cluster, you really need to look at what this licensing change means for you.