Our MP is SCOM-platform-agnostic and should work on both SCOM2007R2 and SCOM2012, then it depends on SCOM - how correctly they will convert the data from SCOM2007 format to SCOM2012 format. Our components don't "talk" with SCOM agent, they just collect information and then SCOM agent "consumes" it, so our collectors even don't know which version of agent is doing that.
What I'm worried about is our reports, but again it depends on how well SCOM is upgrading SRS for SCOM 2012. But I beleive that you can completely remove reporting role and then install it again and SCOM should re-deploy reports from the corresponding management packs.
Hope this helps.