If I could buff one thing...

In all the talk about buffs accross all three trees, one particular buff comes to mind for me: Nemesis cooldown reduction increased to 11/22/33% (up from 10/20/30%). This is particularly with an eye at talents like Intensify Rage as it applies to Death Wish.

Doesn't sound like much does it? It won't even buy you one extra demonic empowerment in a raid. But what it will do is make metamorphosis a 2:00 cooldown, not a 2:06 one.

Why? Because a good deal of fights are built rather cleverly around the common 2 minute and 3 minute cooldowns, meaning that critical phases like nether portals on Jaraxxus and most recently slimes on Putress often line up very closely with a number of cooldowns. Metamorphosis is an odd man out, it literally doesn't line up with anything as cleanly as it could with just 6 seconds off the cooldown.