I wasn't expecting the complete reworking of the rune system.
Of course some caution will be needed, but the way the outlined it, it fundamentally seems like a radical hypersemplification of how the class works. I'm not really looking forward to seeing WoW become even easier that it is now, in all honesty, but in a way it's understandable that Blizzard may want to scale down the complexity of the class - while it's not particularly harder to master than other dps classes for "advanced players", it seems to be brutal on beginners, as any visit to VoA probably can show.
I'm absolutely underwhelmed by the direction of the 3 new abilities.
Outbreak is a mystery. It sounds completely useless as it's written. With a cooldown higher than 20 seconds, I don't see it impacting any pve dps or tanking rotation in any meaningful way. With a cooldown compatible with refreshing diseases, you would get a built in GoD mechanic, whose purpose would fundamentally be that of killing PS and IT forever.
So either it's a completely useless tool (outside of Pvping) or it's an attempt to rework the GoD mechanics into all DK dps rotations, and that would mean a massive change in the baseline abilities are balanced. On one hand tho, with the new Rune system taking disease application off the Rune chain could be part of the plan.
The other 2 abilities seem to be completely PVP based. This is my biggest perplexity - nothing of what was announced is actually PVE oriented. It may just mean that they plan to work the PVE abilities in the talent trees, but still it's puzzling
There is a chance that Dark Simulacrum's core functionality will actually have some PVE flexibility. Something like having OB hitting for 15k and Dark Sim for, say, 9k, but with a pretty wide list of pve abilities that you can copy. DarkSim doesn't need you to be the target of the ability, as worded. If the list of PVE-copiable abilities is long enough, it may actually become an interesting sub-2min cooldown strike that you fundamentally use every time the boss is gonna unleash some vicious spell to get a damage boost. Could actually be interesting.
I'm extremely perplexed about UH and Frost's masteries. UH being even more based around diseases will alienate me further from the specc - UH needs to be LESS passive and not more. Spell and melee crit damage does sound interesting for a specc that has some solid +crit talents (supposing they will surive the Cataclysm).
Frost being haste based could work well with the DW/2h project. The 2h variant will be certainly more strike-based than the DW one, so probably we could see differences in AEP of Mastery etc, leaving some theorycraft to be done.
And of course, even if I know it's just damage control and an emergency move, I'm stocked about seeing Frost 2h back.