I had the opportunity to play a Death Knight for a while at the 2008 Blizzard Worldwide Invitationals.  The Death Knight is first played as a level 55 hero class.  Most of what was shown there may have been incomplete, or Blizzard didn’t want to show much of the Death Knight until Closed Beta.  The location we were sent to at character creation was the Eastern Plaguelands.  There was an intriguing spell named:

Death Gate
Requires level 55
Cost: 1 Unholy Rune
10 sec
15 minute cooldown

Returns you to Ebon Hold.

This spell is intended to teleport the Death Knight to the Ebon Hold, the starting location for the Death Knight (thanks Eldorian).  There was no Ebon Hold to be seen in this 2008 Blizzard Worldwide Invitationals build, so it took us instead to … Tirion Fordring’s house in the Eastern Plaguelands.  This spell seems to be the equivalent of the Druid’s teleportation to Moonglade.  Ebon Hold—wherever it ends up being at—is where the Death Knight upgrades spells and abilities at, and acquires special classs quests.

Depending on the talent tree chosen, the Death Knight can be an asset to a raid. It can either heal the group in special circumstances, give strength aura to all party members, increase speed with Unholy Aura (which stacks with other speed increasing buffs), increases the damage output of a single player: Fury/Prot tank, Shaman, Druid, Rogue or Weapons Hunter with a special buff that sets you into a Frenzy. Transforms itself into an undead for few seconds to become immune to sleep, fear, and charm (perfect for tanking). While in Frost Presence, increases the total health of all party members within 45 yards by 2% and increases your Frost Resistance by 22 with Frost Aura—not bad for Northrend dungeons where certain bosses will do frost damage. And much more.

The Unholy talent tree allows the Death Knight to summon a combat pet: A flipping Gargoyle! And allows the Death Knight player to rise to fight as a Ghoul upon death for 45 sec.

The Death Knight looks like a very desireable class to level up and play in dungeons. I recommend it as an alt character.  It will be a very sought class in LFG channel when there is lack of tanks at certain hours of the day/evening.

Things may change before Closed Beta and even after game release, but I got for you some juicy look into the Death Knight’s Talent Tree. I will let you take a sneak peek at the Blood Talent Tree, the Frost Talent Tree and the Unholy Talent Tree.