I'm having some trouble filling out the last few points of my 80 spec. I'm planning this around tanking 5-10 mans, as my schedule does not currently mesh with my guild's raid schedule well. I'd like some input and discussion from intelligent people on the relative benefits of several talents.

Starting from here: Talent Calculator - World of Warcraft

It's a pretty standard frost tank spec, with the Icy Talons line since lower-size instances aren't as likely to have an enhancement shaman, and if they do, they can probably drop WoA or something of that nature and not run into other buffs that don't stack with those. I did take Icy Reach which I have in my current spec and find invaluable for general pulling and ranged-tanking purposes.

Talents I'm considering for the last 6 points:
- Subversion: Obliterate crit seems good. On the other hand, I'm often using my FUs on HB.

- 2H Spec / Dark Conviction: Decent threat filler if I don't find anything else to drop the points on.

- Rune Tap / 1x Imp Rune Tap: Seems pretty lackluster, but it's another oh crap button.

- Deathchill: Makes Howling Blast give lots of burst threat, but can't be used consistently on every AoE pull, so doesn't really seem too hot to me. I guess it would be an AoE taunt of sorts, which is something I've often felt I lack.

- Blood of the North: Good for single target threat / DPS but for general AoE tanking purposes I'd use Pest/BB or Pest/DnD with my blood runes even if they were death runes, so seems quite skippable.

- Acclimation: Lackluster but it's the only 'mitigation' option which makes it worth considering.

- Hungering Cold: Good effect for those 'oops someone pulled the entire room' situations, but the steep RP cost and the fact that it's likely to just break from random whirlwinds or people AoEing early make it seem really... not good. It does provide a sort of AoE taunt like effect but much less so than Deathchill/HB.

- Morbidity: I very rarely DnD except to gather mobs initially; I find Pest + HB to be a better use of runes in general. So the cooldown reduction doesn't seem great. The benefit of this talent is that with 3/3 you get to spam DnD on every cooldown out of combat and gain net RP so you can start fights out with 100. Gimmicky, but could be useful particularly if I take HC.

- Epidemic: I have this now and I don't like how my diseases fall off if I try to do a second rotation without PS/IT (on single targets). On multi targets I'll be using Pestilence every rotation. So is this really needed at all? I'm definitely leaning towards at least trying a spec without it and seeing how it works out.

I guess I'm leaning towards Subversion, Deathchill, and dropping the last two on Dark Conviction experimentally, moving them to Epidemic if I feel it is necessary.

Outbreak just says it's a 30% damage bonus, it's as simple as that. Your AP coefficient is calculated, impurity bonus is added on if you have that, and at the very end, you add 30% more total damage.

Ok cool thanks, it's starting to click now. Since all a DK spell damage is boosted by our AP right?

And DK's should NEVER ever get Spell Power gear?

It might be more intuitive to think of it as increasing your attack power by 25% for the purpose of spell scaling.

Does anyone know why the DPS Compendium suggests to use UB as a regular part of your damage rotation? According to the coefficients in that post and my napkin math, below, DC should outperform UB in terms of damage per RP assuming single-target once you pass ~1400 AP.

If my math is accurate, it seems to me that you should only use UB if you are below 1300 AP, AoEing, or you get some resists or misses and so are both GCD-starved and RP-capped, none of which should be the "typical" rotation in a raid.

It shouldn't matter. However, if you are planning on tanking at all I would discourage you from making this shortcut- if you are going unholy. Unholy Blight is a key part of our AOE aggro and having a runestrike at the wrong time can really mess things up.

Does it make sense for a DK to stack a bit of spell penetration for PvP, so that disease and scourge strike damage gets through buffs such as shadow protection, mage armor, and mark of the wild, or does this stat have no effect for DK attacks?

Octaviann: The Rune Strike cast should come first. Rune Strike does not cause a GCD, so you can queue it up and then use a GCD-causing Strike within the same button-press, so long as you follow that order. If you try to use a GCD-causing Strike before the Rune Strike, you'll be in the GCD by the time the Rune Strike line tries to execute, and thus it will fail.

Calidar: Two-Handed Weapon Specialization is a direct increase to your weapon damage. Anything that is based on weapon damage such as auto-attacks and Strikes will therefore gain from THWS. Abilities that have nothing to do with weapon damage, such as DOT damage from Icy Touch and Plague Strike, or Howling Blast, or Death and Decay will not be affected.

This is identical to an Arms Warrior's and Ret Paladin's Two-Handed Weapon Specialization. Auto-attacks, Mortal Strikes, Crusader Strikes, Whirlwinds and Divine Storms are affected, but not such things as Consecration.

Note that this is different from the Protection Paladin's One-Hand Weapon Specialization, which is a 10% increase to ALL damage, as long as a one-hander is equipped.

I think he wants to know if the entire strike is increased by 2% or just the weapon damage portion of it. I'm curious about that also. Heart strike, for example - is it 60% WPD *1.06 + x, or (60% WPD + x) * 1.06?

Only the weapon damage portion of the Strike would be affected. Technically, the formula would still be: (60% WD + base damage + (disease bonus * number of diseases)), since the 6% increase to weapon damage would be factored in beforehand.

That is true. This macro is beeing widely shown on many sites as one the most useful but it does not work: if both spells are available, it will cast both and thus killing the second spell cooldown, which is bad as Strangulate has a 2 minutes CD. I did this macro in order to keep my hotbars clean:

So I can use my ranged silence by "alting" my standard silence key.