Checking MMO-Champion, we recently discovered that they posted a listing of what appears to be Blizzard's patch notes for the friends and family alpha of Wrath of the Lich King. The report is currently unconfirmed, however, so you'll have to take these notes for what they're worth.

Note that, in this set of patch notes, the Death Knights are already playable, with some of their skills and quests (not all, sadly) already intact. Furthermore, there are already some dungeons available for play, which is also way cool.

In any event, below are the rumored patch notes given for the friends and family alpha of WotLK:

World of Warcraft: Wrath of the Lich King: Friends and Family Alpha

Welcome to the World of Warcraft: Wrath of the Lich King Friends and Family Alpha. The list below contains information on the current available content available for testing and general information. This information is subject to change.

General

• The continent of Northrend is now available!  To travel there, visit one of four transportation masters in either Orgrimmar, Undercity, Theramore,or Menethil Harbor.
• Transportation between Howling Fjord and Borean Tundra can be found at the Tuskarr villages in those zones.
• NPC Transportation Locations
• Horde:
• Undercity to Vengeance Landing (Howling Fjord)
• Orgrimmar to Warsong Hold (Borean Tundra)

•    Alliance:
• Menethil Harbor to Valgarde (Holwing Fjord)
•    Theramore Valiance Keep (Borean Tundra)

World Environment Zones

• The following zones are available for testing: Howling Fjord, Borean Tundra, Dragonblight, and Grizzly Hills

Dungeons

• The following dungeons are available for testing:
• Howling Fjord: Utgarde Keep (70-72)
• Howling Fjord: Utgarde Pinnacle (80)
• Borean Tundra: The Nexus (70-72)
• Grizzly Hills: Drak’Tharon Keep (74-76)

Classes

• All Classes are available for play.  Spells and talents will be available for testing past 70 for the following classes: Druid, Mage, Priest, Shaman, Warlock, Warrior
• The Death Knight Hero class is now available for play.
• Creating a new Death Knight will start you at level 55 in Eastern Plaguelands.
• No starting quests are implemented though Death Knight abilities will be available for testing.
• Several Death Knight talents, although they will appear on the talent pane, are not yet implemented.  

Professions

• The following tradeskills are available to train up to 450: First Aid, Herbalism, Mining, and Skinning.