YAY COLLISION
Readiness and Fury -- Why I'm 99% certain on the abilities that will fall under this stat.
My main argument for this title:
What else are they really going to put on readiness for Fury/Arms that would be valuable?
Bloodthirst is off the table due to head-long rush already reducing that.
Colossus smash would be weird, and unlikely to happen for many reasons (pvp, not useful for arms, the new glyph wouldn't work at all)
Doesn't leave much else. Wild strike/execute are usable anytime, raging blow is a proc from bloodthirst, berserker rage/battle shout don't do anything anymore.
The only abilities that it could reduce are tier 4/6 talents, recklessness, and heroic leap.
Now, for most other specs, it's likely up in the air as they have more to work with or are receiving major changes to their spec. For Fury, the only question at the moment is what will the multiplier be on the conversion?
Game data shows readiness baseline is the same as mastery/crit, 1% = 110 rating at level 100.
Our current trinket will give 99 rating, and according to the same scaling data 1% = 23 rating at level 90, that's 4.304% without any rating multipliers. However, the trinket gives 50% readiness at the moment, so let's just guess that they keep it at 50% readiness for 99 rating.
50 / 4.304 = 11.617~ rating multiplier.
Then, Readiness by itself. The little "kinks" in the line are from a few things, such as where colossus smash and storm bolt line up together, additional recklessness's can be used, or when bloodbath better aligns with colossus smash.
The overall message here is that haste/readiness appear to be viable stats until 2100~ rating where they start to taper off. By the time we have that much rating in either of those stats mastery will have likely climbed out from the dumpster to overtake them.
I put 2000~ crit and 2100~ (224%) readiness on the character. This is probably later 2nd tier-ish gear. Right at the 2100 readiness spot, there rests a place where removing readiness is more of a dps loss than removing crit.
What happens around there?
Storm bolt: 30 / ( 1 + 2.24 ) = 9.25 second cooldown
Bloodbath: 60 / ( 1 + 2.24 ) = 18.51
Reck: 180 / ( 1 + 2.24 ) = 55
Heroic Leap: 30 / ( 1 + 2.24 ) = 9.25
Die by th... hah, i'm fucking with ya.
It's the perfect storm. Bloodbath can now be used every CS, storm bolt can be used every CS, and now recklessness is used every 3 colossus smashes. Oh, I'm wearing a trinket that also procs every 50-55~ seconds to line up with that reck.
After that, everything gets desynced and the value of cooldown reduction falls dramatically.