Omen's single target threat list is nice, but what DDs really need to know is how much damage they can do. To Mind Blast, or not to Mind Blast, that is the question. Probably even more important for Warlocks. So the interesting numbers are
threat buffer = (tank threat)*130% - (my threat)
damage buffer = (threat buffer)/(my current threat multipliers)
What I'd like to see is just a numeric display of this "damage buffer". Most of the time, it would be more useful to me than Omen's threat list. I'm not sure exactly where to implement this. A stand alone addon? Or a new Omen module? A column in Omen's threat bars would be nice; especially for encounters where DDs have to stay below the second or third tank.
And yes, I know this is not very general. Abilities with innate threat wouldn't be covered, or fancy stuff like the Prism of Inner Calm. However, most abilities of DDs don't have innate threat, most DDs don't wear that trinket, so providing a somewhat accurate estimate should be doable.
As a Damage Dealer you should know your "crit spell" threat normally :P
With your Idea they still would need to know how much damage they do, for classes with DoTs this even gets more complicated, which is about as complicated as knowing your spells threat value when they crit...
In the end the calculations are the same you have to do in your head:
if TankThreat - MyThreat > MyMaxThreatMindBlast then
/cast Mind Blast
if DMGIamableToDo - MyHighestCritDMGfromMindBlast > 0 then
/cast Mind Blast
I dont really think the second one is that much easier :P
Not to mention in the time you are doing that decission the Tank already built an additional 200Threat most likely :P
Really good idea. That would be a nice module to add to any threat addon. It calculate your threat in your doing with each spell on the current mob with each spell, then show you an average of damage you can do. It could also presume how much threat the tank will have done by the time of cast for more accurate value. I would like to have 2 value one really safe and another one that could pull aggro.
It could also alert you that will pull aggro BEFORE even finish casting.