Protect your neck
Necklaces are a new valor point buy for this tier. For tanks, the Stoneheart Necklace is a pretty pro buy. Mastery and parry rating are both solid, so this'll definitely last you through Firelands heroic drops.
For DPS, the Stoneheart Choker is a much more problematic piece, due to the fact that it has critical strike and expertise rating. Critical strike is mediocre at best for death knight DPS, and unholy also tends to favor haste and mastery over expertise. As a result, you unholy DPS death knights may just want to pass on the necklace unless you can't get a Firelands drop and have nothing else to buy. Frost can still get use out of the choker if you need the expertise, though. Just reforge the critical strike rating to haste.
Lording over rings
In other jewelry options, we do once again have some rings for sale. The Deflecting Brimstone Band is your tanking option, containing dodge and mastery. Tank valor point itemization is pretty awesome for tanks this tier, and this ring is no exception. Buy it, wear it, and you've made a great choice.
DPSers can pick up the Serrated Brimstone Signet, which has the awkward combination of haste and critical strike rating -- the best death knight DPS secondary stat combined with the worst. Still, the haste makes it worth using, although a lot of DPSers may see themselves dropping this ring for Alysrazor's Band if they need some extra expertise.
A range of relics
If there's a safe buy for your valor points, it's the relics. These relics will last you for a long time -- probably the rest of tier. You'll even upgrade them to heroic level with Crystallized Firestones.
The Deathclutch Figurine is your tanking option. You'll still want to keep your parry and dodge relatively balanced, but if one of them is significant higher than the other, you can always reforge it to mastery. For DPS, you'll get the Relic of the Elemental Lords. Reforging the critical strike rating to mastery (or hit or expertise, if needed) should do you find for this one.
Binding bracers and gaming the system
Bracers are the BOE option for you this tier. The Bracers of Regal Force are your tanking options. With a lot of dodge rating and a little parry rating, they're a great way to make up a dodge deficit. And of course, if they give you too much dodge, you can reforge them to a good chunk of mastery.
The Gigantiform Bracers are your DPS option. Mastery is a pretty solid middle-of-the-road secondary stat for all DPS death knights, and everyone needs hit rating as well. Your basic question in buying these is to figure out whether you need the hit rating or not. If you don't need the hit rating, you may just want to wait for Earthcrack Bracers to drop.
It's also worth paying attention that whole BOE thing. If you're an altoholic like I am and you have multiple heroic-ready level 85 characters, you can let them do your work for you. Take your alts and run heroics. Once they hit 1,250 valor points, buy the bracers and send them to your death knight. That way, you can spend your death knight's VP on other stuff.
Tears over tier gear
Like last tier, you can buy your tier 12 chest, gloves, and legs with valor points. Tanks get the following pieces:
For tanks, it's pretty simple. All three pieces are well-itemized and should serve you well, and as the four-piece bonus is desirable, you'll want to get them. Of course, the two-piece bonus isn't incredible except as a little bit of extra threat, since you'll still want the debuffs from your regular diseases, but more threat is good, too. Also, be aware that Occu'thar in Tol Barad
can drop the legs and gloves, so if you want to be extra stingy, you can buy the chest first and hope that Occu'thar lets you save a couple thousand VP.
DPS will get the following pieces:
For DPS, the argument as to whether to buy the tier gear is a bit murkier. The breastplate, with critical strike and mastery ratings, is generally considered lackluster when compared to the Ragnaros dropped Breastplate of Shifting Visions
. Of course, that means you'll want to wear all four other pieces of tier gear to get the set bonus. So you may end up having to buy the gloves and legs from the VP vendor instead of waiting for Occu'thar to drop them, since you'll have very little better to buy. And of course, if your breastplate isn't dropping from Ragnaros, you'll probably want to buy the chest, anyway.
Learn the ropes of endgame play with WoW Insider's DK 101 guide. Make yourself invaluable to your raid group with Mind Freeze and other interrupts, gear up with pre-heroic DPS gear or pre-heroic tank gear, and plot your path to tier 11/valor point DPS gear.