Yesterday late in the evening Microsoft released the update documentation for SCOM 2012 SP1 to SCOM 2012 R2 RTM. Even though the online document still carries this statement [This topic is pre-release documentation and is subject to change in future releases. Blank topics are included as placeholders.]:
I expect it to be removed soon.
So when you’re running SCOM 2012 SP1 and want to upgrade it to SCOM 2012 R2 RTM, this is your starting point. Please take your time to read it and understand it. Only then it’s time to plan, prepare and finally execute the upgrade itself.