Come 5.0, the old talent trees are out and the new ones are in. It’s a scary change for some people, and yet for others it’s a welcome one. Personally, I’m going to withhold judgment on the new talent system until I have a chance to try it out for myself. That said, I think that I have a bit of insight on all the talents that have been released.
If you’ve not heard yet, the new system is broken up into three sections: Class Abilities, Spec Abilities, and Talent Abilities. Class Abilities for are abilities that everyone who is that class has no matter what spec they are. For DKs, this includes things like Death Strike, Pestilence, and Plague Strike. Spec Abilities are the abilities that come from the spec you’ve chosen. For Frost DKs, this is Howling Blast, Frost Strike, and the like.
Talent Abilities are abilities you select as your talents. In the new system, there is going to be six sets of three abilities that all share a common theme. You can choose ONE of these abilities. Each set is separated by a 15 level gap. For Death Knights, this means you’re going to start with the ability to pick three new talents right at the start. Here’s what your talent tree is going to look like:

So much simpler!
Before we cover talents though, there’s one thing you all might be worrying about…
AAAHHH! WHERE’S MY STUFF?!
If you take a look at the list of abilities, you’re going to notice that a lot of your passive abilities are missing. Don’t worry, they’re not gone. Instead of having Icy Talons or Killing Machine be normal talents, they’re now your passive Spec Abilities for Frost. Here’re the frost-specific talents that made the jump to Spec Talents:
Blood of the North (55), Icy Talons (55), Howling Blast (55), Frost Strike (55), Obliterate (58), On A Pale Horse (61)*, Killing Machine (63), Pillar of Frost (65), Rime (70), Might of the Frozen Waste (74), and Threat of Thassarian (74).
* – On a Pale Horse is a Class Talent. All death knights will have it.
To recap, this means you’re not losing your autocrits on Oblit, your free Howling Blasts, or your 30% chance to hit with your offhand on certain attacks.
However, what does appear to be gone at this time is Nerves of Cold Steel, Endless Winter (for free interrupts), Merciless Combat (12% increased damage on mobs below 35%), and Brittle Bones (4% increased strength and increased physical damage), among others.
Now that we’ve covered what’s staying and what’s going, here’s how our talents seem to break down:
LEVEL 15: SPREAD THE SICKNESS

Roiling Blood – I like the theory behind it for trash packs. It would replace Pestilence in a rotation, giving both a little bit of damage and causing a pestilence for every diseased mob it hits. The nice thing is, if you’re fighting two diseased targets, they’ll refresh each other, so you don’t have to reapply diseases to your target. However, it does not help you at all against bosses.
Corpse Explosion – This one amuses me, but I don’t think it has as good a combat ability as the other two. It requires that you’ve already killed something, which means that you are probably nearing the end of the fight anyway.
Outbreak – No change from what we’ve got. Compared with Roiling Blood, you don’t get damage from the pestilence of Blood Boil, but you save a unholy rune every minute (your frost fever is never going to fall off due to Rime procs). Also, if you take Roiling Blood, you’ll need 2 GCDs to apply both of your diseases.
My Choice: Outbreak/Roiling Blood. I honestly can’t pick between the two. I’m leaning outbreak, but I want to give Roiling Blood a shot, just to see if it makes any difference at all.
LEVEL 30: DAMAGE MITIGATION

Lichborne: Same as what we’ve got now. The immunity is decent in PvP as well as any fights with charm, sleep, and fear effects (which would probably be ‘none’), however it can be combined with Death Coil to heal yourself. Personally, I never have the RP necessary to heal myself properly with this method, so I’ll pass.
Anti-Magic Zone: A raid cooldown, kinda. It’s an AoE damage reduction. Works as seen in the game now, but for any spec.
Bone Shield: Also one we’ve got now. It’s your personal damage reduction, on a minute cooldown.
My Choice: Bone Shield, unless the raid is light on CDs. Then I’d swap to AMZ. Bone Shield’s up-time should be 100%, so you’re taking 20% less damage at all times. Sold.
LEVEL 45: CONTROLLING THE CROWD

Death’s Advance: PvP talent. I’m sincerely disinterested.
Chilblains: Same as what we’ve got now. I love these things, but I’m always the one kiting. If a fight doesn’t have adds, it’s useless, but then again, so is anything in this tier.
Asphyxiate: this was infinitely more awesome before they added the 5 second duration. As it is now, it’s a neat little gimmick. It replaces our ranged silence with a ranged stun that acts as a silence if the target is immune to stuns. It also has half the cooldown as strangulate. Interesting, but I don’t like it.
My Choice: Chilblains all the way. I love these things.
LEVEL 60: HEAL MEH!

Death Pact: I have two main complaints: the cost (40rp and a ghoul) and the cooldown. As frost, your ghoul is a 3 minute cooldown and is probably macroed into your pillar of frost, so it’s almost never up. No ghoul, no DP, and you don’t get your health. Even if it was up at the right time, you’ll lose DPS by losing your ghoul prematurely.
Death Siphon: A new one. It’s basically a Death Strike that costs a death rune, as opposed to a normal one. Unholy will like this one, as it’s probably affected by their mastery. Frost, it’s more iffy than not. 75% of (the unmodified) 3116 the tooltip shows isn’t a lot in terms of healing.
Vampiric Blood: You get health, increased maximum health, and increased healing. On a minute CD, I like vampiric blood a lot. You can use it to pick up 15% life long enough for the healers to pull you back up to full on fewer spells.
My Choice: Vampiric Blood. Unless Death Siphon does way more damage or our health pools get squished to having 8k being a lot, I’ve got to give it a pass. I can see VB saving me way more often than DS.
LEVEL 75: RUNIC RECOVERY

Blood Tap: Old, but changed. The 1 minute cd was removed, making it infinitely more viable. However, my biggest complaint about Blood Tap compared with everything else is it’s on-use. If you forget about it, you’re never getting runes back. DKs already have a lot to think about; Rune Recovery shouldn’t be one.
Runic Empowerment: What we’ve got now as frost death knights. I can live with it.
Runic Corruption: What unholy death knights have. The buff stacks instead of overwrites, so if you get it to proc with 2 seconds left, you have 5 seconds of regen, not 3.
My Choice: Runic Corruption. I’ve been waiting for this for a while. Hopefully it’s going to make frost much less RNG-based than it is.
LEVEL 90: GETTIN’ FANCY

Gorefiend’s Grasp: I love the idea of a targeted AoE death grip. Use it seriously to pull adds to a tank… or use it to be a dick and pull all the adds to your healer. (Don’t do that, or you won’t get heals next boss >.>). It makes me laugh just reading it.
Remorseless Winter: Possibly the coolest DK ability. It’s an AoE slow, that turns into a stun, that doesn’t need to be maintained. While the range is a little short (only 10 yards), you don’t need to stop what you’re doing to use it. Snare trash or adds, or even use it on a boss for a little extra damage. A flat-out amazing ability.
Desecrated Ground: Kinda reminds me of Desecration. It’s with Lichborne as a PvP ability in my mind, however. Plus, it does less damage than Remorseless Winter on a twice-as-long cooldown. It just can’t compare
My Choice: Remorseless Winter. I suspect you’re going to see a lot of DKs with this. Gorefiend is funny, but not anywhere near as useful.
Despite my thoughts, feel free to pick whichever you like from each. Blizzard has said they are attempting to cut out min/max builds where everything is optimized for DPS.