WowAce

Tracks specialization and talent data for group members

Inventory and bank organizer.

Overlays Archaology digsite icons on the flightmap

Records mail when visiting the mailbox to make keeping track of mail and expiration dates easy.

Scaffold

Fubar Plugin for Simple Soulstone

RainbowEnchants

NiHao

An addon that automatically loots items for you.

Adds Blizzard, oRA2, oRA3, CT_RA MainTank or Dungeon Finder Tank icon (shield or MT, 1, 2 ... 10) or text (MT or MT1, MT2 ......

Audible Alerts for self-gain, self-lost, any-gain, all-lost of statuses.

Damnation

Shows more recipies in the profession window.

View party member quest logs

For Developers (of Addons which uses LibWho-2.0): show queues and queries in realtime

Allows combined aura detection. motw + gotw, all 4 mage int buffs, etc. in one status.

TGuildFrame

Provides extended aura status settings.

Gives equipped and overall iLvl to indicate the quality of a character's gear.

Interface for addons to include extra information on the GuildMemberInfo frame.