To the right you will see the damage done and damage taken from a Heroic CoT run last night. These are the overall numbers and individual bosses usually had my damage lower than everyone else.
Needless to say, when the tank takes 72% of all damage in the run, and I didn't try to pick up the little zombies, I think it's safe to say I did not have any issues holding threat.
However, I did feel that both my AOE and single target
It could be due to the change in runestrikes damage. I know it is supposed to have a 1.5 threat modifier.
Rune strike went from being my number 2 source of damage on heavy AOE tank runs (DnD beat it out) to number 6 with it's damage contribution cut in half.
Until I get a few more runs under my belt post patch, I think the jury is still out on Unholy threat production.