Hey David,
There won't be comprehensive information available on our 3.12 kernel features until we roll our SDK out in March, so expect to see feature lists and driver guides around that time.
As for the the PM stuff, it's still being worked on right now. There was a major shift in architecture going from 3.2 to 3.12 that affected PM for AM335x, so we won't be sure exactly what the drivers will look like until they are completed in the next few months.
Regards,
Josh