Death Knight: Frost

Frost is a highly mobile melee DPS spec which rewards proc awareness with spike damage and large amounts of variable damage- by this I mean damage that's just as good single target as it is for AoE. It suffers from the usual melee DPS concerns (roots, etc) as well as the fact that if you need to NOT be using AoE- for example, if you need to not be hitting an add that happens to be near your target- you lose out on quite a bit of damage. Frost provides a raid-wide attack speed buff as well as a 4% melee damage increase on the Death Knight's target. As with all Death Knights, they also provide the STR/AGI buff through Horn of Winter.

 

Stats/Gearing:

 Frost Death Knights primarily look for Strength and Haste on their gear. The stat priority is as follows for both specs: 

Strength > Hit (to 8% cap) > Expertise (to 781 expertise rating) > Haste > Mastery > Crit  

Gems:

Bold Inferno Ruby, Fierce Ember Topaz, and Etched Demonseye are the gems you'll be wanting to use, depending on the slot color.

Runeforge: Rune of the Fallen Crusader for 2h. Rune of the Fallen Crusader/Rune of Razorice for DW

 Talents:

Frost can be specced one of two ways: for dual-wielding or for a 2-handed weapon. The template specs are as follows:

Frost DW

Frost 2h

The extra points in these builds can go into one or more of the following:

Runic Power Mastery: Reaching your Runic Power cap is wasting potential RP. Taking this talent gives you a bit of leeway in how you spend/reserve it so you're not wasting any.

Icy Reach: Howling Blast is a huge part of Frost's DPS, and giving it extra range helps during certain phases of certain fights.

Lichborne: Useful for certain situations in which you'd otherwise be useless to the group (or, in the case of Charm effects, dangerous to your group members)

On a Pale Horse: Mount speed is useless for raiding. Snares rarely happen. PvP talent, has little to no use in PvE.

Endless Winter: Free Mind Freeze. Considering Frost Death Knights pack one of the best interrupts in the game, making it free is never a poor choice. 

Chillblains: Useful for adds, but can be annoying for tanks. This one depends on your group's needs.

It's also important to take note of Frost's innate talents- the powers you get upon selecting Frost as your primary talent tree:

Blood of the North: Your Blood Runes are permanently transformed into Death Runes. This makes the usage of Obliterate quite a bit easier.

Icy Talons: Increases your melee attack speed by 20%. That's about it. It's not 20% melee haste, as that would give a bonus to rune regeneration, which is somewhat important to know.

Runic Empowerment: Whenever you use your Frost Strike, Death Coil, or Rune Strike, you have a 45% chance to activate a random fully depleted rune. This is why you want to be using Frost Strike after your other abilities- to randomly regenerate runes.

Runic Focus: A nice bonus to Howling Blast and disease damage, as well as halving the amount of hit Frost Death Knights need- which just so happens to put them on par with other melee classes.

Glyphs: 

  

Prime: Frost Strike, Howling Blast, Obliterate

Major: Anti-Magic Shell, Dark Succor, Hungering Cold, Pestilence

Minor: Path of Frost, Blood Tap, Horn of Winter

Rotation/Priority:

Both specs should be using Unholy Presence at all times apart from extreme AoE needs, which will use Frost Presence.

Single Target:

>Apply your diseases with glyphed Howling Blast and Plague Strike/Outbreak.

>Obliterate when Killing Machine is procced or to consume runes.

>Frost Strike when RP-capped, when Rime procs, or when your runes are fully depleted. 

>It's worth waiting ~2 seconds for a Killing Machine Obliterate- if it's going to take longer than that, consume the Killing Machine proc with Frost Strike. 

> If none of the above are available, toot your Horn of Winter.

Multi-Target: 

Multi-target Frost barely exists- unless there's swarms of enemies, you're best off selecting one at random and using a single-target rotation. However, when faced with immense need for fast AoE:

>Death and Decay

>Outbreak

>Pestilence

> Howling Blast spam

>Frost Strike when out of runes. 

Cooldowns:

 Pillar of Frost: Basically, a 20% damage increase. Also, the only Frost-only cooldown. What's nice about this is it actually increases your Strength by 20% instead of simply giving you a 20% damage boost, which makes it synergize well with...

Raise Dead: Raises a ghoul to fight with you for 1 min on a 3 min cooldown. The ghoul has stats that reflect your stats at the time of his raising- the best time to raise a ghoul is during Bloodlust with Pillar of Frost up. 

Army of the Dead: This will either massively increase your DPS or wipe your group. Army ghouls, unlike the one from Raise Dead, will taunt anything they attack. If something needs to be moved in a specific manner or needs to be targeting the tank, Army will fuck it up, hard. Make sure a fight is safe to use Army on before using it.   

Raise Ally: Our new Battle Res. Pool up some RP to cast it on an ally for an instant res- making this the best battle res in the game. Having said that, knowing who to cast it on is rather important- when faced with a choice, it's always best to bring up another player with a battle-res. Having said that, the usage will vary wildly depending on what's going on- communicate with your group.

That's about it for Frost Death Knights. This post will be updated as patches come and go and as more information is made available to me.