MMO-Champion first rushed the images to us and I likey what I see!
My link comes from [Epic] Wins, which is another nice site that delivers the news (and my work filter doesn't block it).
I don't know if I like the blue aura on the red shoulders, but in general I really like the design. The shoulders look more menacing and powerful than the T9 ones, and they also carry on the tradition of having skulls in prominent places.
That sword though, oh my!
It's the most delicious thing about the armor set. One wonders if we'll be able to get that one somewhere in Icecrown and how good it's dps/stats would be. I have a feeling that were I to get that one, even if I had a better weapon, that would be my Dalaran armor set. ^^
I'll be eager to see the stats on the gear and how they balance the armor pen vs haste etc issue.
Forgot to comment on the set bonuses:
T10 Death Knight Tank 2p Bonus: Increases the damage done by your Death and Decay ability by 20%.
T10 Death Knight Tank 4p Bonus: When you activate Blood Tap, you gain 12% damage reduction from all attacks for 10 sec.
T10 Death Knight DPS 2p Bonus: Your Obliterate, Scourge Strike, and Death Strike abilities deal 10% increased damage.
T10 Death Knight DPS 4p Bonus: Whenever all your runes are on cooldown, you gain 3% increased damage done with weapons, spells, and abilities for the next 15 sec.
Those are nice. It's been pointed out those could be placeholder values, and they may, but I can drool, can't I?