You've faced the rising power of the Scourge and its master the Lich King, and you've realized that you, at least, are not going to stop it. Maybe you fell fighting it and then joined its ranks, keeping more of your mind than most undead. Maybe you despaired of life's prospects and joined up with it out of a sense of inevitability. Maybe you embraced the darkness willingly. One way or another, you find yourself in the heart of the Scourge's growing empire, the floating necropolis known as the Ebon Hold, and facing your new overlord very directly.
That's the setup for the new death knight character class. I'll be illustrating my experience with it via my blood elf Cleitus, supplemented occasionally with pictures taken while playing night elf Syyind.
This is what I saw first: a balcony of the Ebon Hold, with valkyries on either side and the Lich King himself straight ahead:
Cleitus, in the standard regalia of the new death knight initiate (with helm and cloak hidden, as is my wont):
One of the valkyries:
And the Lich King him/itself, who acknowledges the new recruit...
...and sends them off to Highlord Darion Mograine, who handles a lot of the actual operations of the Hold:
(One nice touch is that the Lich King is often talking while nobody is at hand, sometimes to himself and sometimes obviously giving orders or receiving reports telepathically. His voice is a presence in the character's mind from time to time throughout the starting sequence.)
Training gets right underway with the character taking an available sword, learning the basics of runeforging to make it magical, and adding runic power. The death knight gets a whole bunch of new graphics of supreme coolness, like this flaring and cooling pattern after successful runeforging:
The new recruit wastes little time with the sword unbloodied; the next step (which I didn't end up with good shots of) is to select any of several shackled unworthy initiates...
...and duel them down. (The target gets time to retrieve weapon and armor, but even so, it's a pretty harsh setup.)
Then it's time to spy out the targets of the Lich King's next assault, on the Scarlet Crusade-built enclave of New Avalon in the eastern Plaguelands:
And then it's down to the launching point for the invasion. Yes, that is a skeletal gryphon with blue fel energy glowing in its chest cavity, as with the dragon in the Lich King trailer.
The invasion's launching point looks like what you'd expect a Scourge gathering to look like:
New Avalon is, at this point, still in good shape:
Notice the contrast between the tainted sky and blighted ground around the Scourge camp and the field where Cleitus stands, down the slope from those archers. That's all going to change, thanks to Cleitus and the army he's with.