WowAce

Keeps track of people who have recently sent you messages.

BigWigs_RazuviousAssistant

Uses TomTom to show target location if target is in party or raid.

Darkness

Uses linear regression and a log of hitpoint values to estimate how long a boss has left to die and reach execute range.

Add timer to the build-in spell alert

RBM_Hyjal

Addon to manage WoW titles.

Broker_Tracking

FuBar_AlarmClockFu

QuoteNoMore

Experimental timer library that uses the Animation system as a scheduler.

Logs hunter's use of Feign Death

Library to handle and store information about frame that are possible targets to anchor other frames to.

Really very early stage. No, earlier than that.

Tracks and reports party rolls

A Data Broker plugin to display how long you've been playing

OneStorage

LibRockConsole-1.0

Simple loot specialisation display with selection in tooltip.