Frost dual wielding gets a hand up
While Might of the Frozen Wastes was nerfed in order to bring 2H frost in line with dual wield frost, dual wielders got one more buff at the last minute. Killing Machine once again procs off of off-hand attacks.
Tests from the PTR suggest that this definitely results in more procs, enough to boost dual wielding to 2H's level, if not slightly past it. Of course, dummy tests and sims always have a high chance of inaccuracy, so we may have to see how it fares in the game once more death knights have a chance to get their feet wet. Regardless, it is relatively safe to say that if you want to switch back to dual wielding with patch 4.2, you will probably be able to swing it. At the least, it should be more or less equal to 2H frost, and likely a slight bit better, enough that I'd almost expect (or hope for) Blizzard to reverse the Might of the Frozen Wastes nerf in a balance patch at some point before patch 4.3.
Unholy gets stronger, in theory
The long neglected unholy tree got a quick infusion of buff power as Unholy Might shifted from 5% to 20%. This would appear to buff it nicely in the short term. Preliminary tests suggest it will now be the best DPS spec as late as the normal tier 12 gear level, as strength works nicely to buff existing damage, including on the ghoul itself. That said, the buff also brings with it some sticky questions about long-term viability.
The first is surrounding the ghoul. A ghoul is already somewhere around 1/4th-1/3rd of a good unholy death knight's DPS. This Unholy Might buff will only increase that. Certainly, whether or not that's a problem depends somewhat on how you look at death knights. For some, the ghoul is a trusted sidekick, a signature part of the class. For others, it's just there, sort of a free mobile DOT. The biggest issue, of course, is the possibility of the ghoul dying. It's been argued that a death knight is not a pet class, so the fact that you can kill or crowd control a ghoul and immediately take away around 1/3rd of a death knight's DPS has been viewed as problematic.
The other question has to do with weapon damage. Strength simply doesn't scale well with weapon damage. It makes weapons hit harder, sure, but once we get to ilevel 391 weapons, it's looking very possible that frost's superior weapon damage will once again outperform unholy.
So while a quick press of one button has perhaps immediately fixed unholy such that a DPS death knight can take it without feeling complete shame, there are serious questions about long term viability. We'll see how the actual numbers work out as people attack the content, but it may be that Blizzard really does need to do some more tweaking.
A critical issue with tier 12 DPS trinkets
The tier 12 strength DPS trinket issue has also been generating a lot of buzz in the death knight community lately. The Vessel of Acceleration and Apparatus of Khaz'Goroth both grant a buff that triggers from your critical strikes. For frost, this isn't so bad in theory. As frost, you have Killing Machine to grant you automatic melee critical strikes, so you'll be more or less fine using the mechanic.
For unholy, it's a different matter. Not only do you not have a critical strike producer like Killing Machine, but critical strike rating doesn't even get picked up by pets like the ghoul. This means that critical strike is far from a priority for unholy death knights -- the buff from both items will build up to its maximum stack far too slowly. So far, tests from the PTR suggest that if you're a raiding unholy death knight, especially at the heroic level, you'll probably just want to hold on to your Heart of Rage and Crushing Weight.
Blizzard seemed to be making a pretty concentrated effort with ilevel 359 trinkets to avoid the problems with upgradability that occurred in the past, such as Darkmoon Cards being optimal for multiple tiers. Still, it seems they've made a bit of misstep here. It's probably a bit late to hope they'll switch these trinkets to chance on melee hit, or find some other way to buff them for melee specs that don't do many critical strikes, but hopefully it's a lesson they'll take to heart when designing tier 13 loot.
What comes next
While there's still obviously some issues (I will still maintain that the Hungering Cold nerf was undeserved and ham handed, especially when abilities such as Psychic Scream and Intimidating Shout still exist with no cast time), we can probably expect the current death knight DPS balance changes to come to live servers as-is around June 28. From there, we'll see how it all shakes out.
Current conventional wisdom suggests that unholy will dominate at first, but once you get into heroic-level gearing, frost will claw its way back to the top due to superior scaling with weapon damage. Either way, it should be interesting to see where we fall on the DPS meters. Lead Systems Designer Greg "Ghostwalker" Street claims the recent Obliterate and Howling Blast nerfs were because we trended too high on both PVE and PVP damage. Once we've had a few weeks with Firelands raids, we shall have to see whether the raiding community's performance agrees with his assessment.
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