The ever-helpful Ghostcrawler hit the forums late yesterday with a slew of changes to Death Knight tanking in the form of both bug fixes and buffs. The single biggest "buff" is actually a fairly significant bug fix; Death Knights had half the untalented, ungeared dodge of a Warrior or Paladin, and that was definitely never intended. Between that and a change to Blade Barrier (it's currently activated with all runes on cooldown; it's being changed to activate with only Blood runes on cooldown), Death Knights should see a significant improvement to their avoidance. Threat generation is also getting a nice boost, as Blizzard recognized that Death Knights suffered badly whenever key moves failed to land. Rune Strike is becoming a reactive ability like the Warrior's Revenge, and Frost Strike can no longer be dodged, blocked, or parried. Death and Decay has also been changed to be more competitive with Consecration and Thunder Clap, which is consistent with the overall trend toward AoE tanking effectiveness.
I've healed a number of Death Knight tanks in 5-mans now (you'll be hearing from my grumpy self about this soon) and recognized a few early versions of these issues, certainly in the form of Blade Barrier's often-spotty uptime. While I'm glad that DK's are getting more consistent threat generation, I have to admit that my real concern is the amount of burst they seem to take (something others have noticed as well), so I'm keeping an eye on the tweaks being made.
Thanks to Doug for writing in!