Here is an interesting question / theory depending on your point of view.
Windows Server 2012 was Beta in May 2012, general relase was around sept oct, so 14 months after Beta we are still waiting for backup exec to support it.
I have this theory that if Symantec had never released the mistake that was / is Backup Exec 2012 we would already have a released product to support it. In that 2010 r4 or R3 SP3 would have been released long ago and been working. My theory is, the problem symantec have is that they couldn't have BE 2010 backup up something ie windows 2012 that backup exec 2012 could not support, otherwise even more users would have rolled back. The problem is that not only have they had to update BE 2012 to support server 2012, they have had to fix the product, so it is taking a ridiculous amout of time to get the necessary updates released.
So dear Symantec, whilst you are fixing Backup exec 2012, please release the update for 2010, so us frustrated end users can back our servers up !