Leaked from Russian forum:
"With the new introduction to a single Rune ressource system in Legion we felt like it really allowed us to make some major changes to the Frost Death Knight and introduce some depth in the gameplay that wasnt revolved around the runes. At the same time we've heard alot of criticism about how Killing Machine devalued crit and didnt really alter the prioritization of the gameplay much and in the end just resolved in being a flat dmg increase with a devaluation of critical strike. With this in mind we are working on the following changes to Killing Machine:
Killing Machine:
Each ability has a chance to trigger Killing Machine with up to 1 stacks (Can be increased to 2 with talents). Using Frost Strike / Obliterate / Howling Blast while Killing Machine is active will empower the death knight according to what spell is used for 5 seconds. You can have all 3 empowerments active at the same time.
Using Frost Strike while Killing Machine is active will turn all of Obliterates dmg into Frost.
Using Howling Blast while Killing Machine is active will increase the Death Knights rune & runic regeneration by 100%
Using Obliterate while Killing Machine is active will make Frost Strike Cleave with 20% in 10 yard radius."
We felt this change to Killing Machine kept the fun aspect of having to react to procs while removing the annoying devaluation of crit aswell as introducing some choice for Death Knights on whether they want to empower their AOE / ST / Ressource Regeneration capabilities.
We look forward to everyone testing out the changes in Beta!"