Hello.
I registered just so I could submit my suggestions

(I've also been catching up on Ciderhelm's podcasts.)
Might I suggest adding:
Buffs
ZOMGBuffs: "All in one buffing mod for all classes. Paladin buff generated assignments based on Paladin capabilities and raid member sub-classes (druid tank vs. druid healer etc.). Plus overview of important raid buffs, and instant access rebuff on right click."
ZOMGBuffs - Addons - Curse
I've personally found this to be an amazing mod. Slightly buggy in some cases and in development, but very high potential IMHO and still very useful.
Inventory
BankItems: "Remembers the contents of your bank, bags, mail and equipped and display them anywhere in the world. Also able to remember/display the banks of any character on the same account on any server, as well as searching and exporting lists of bag/bank items out."
BankItems - Addons - Curse
I also like this addon because it tells in an item's tooltip if an alt of yours, or your guild bank has an item, such as, if you click on the item link for Saronite Ore, it might say in the tool tip something like:
"Hoey has 4 [Bank 2, Bags 2]"
"Hoester has 2 [Bank 1, Bags 1]"
"<Brotherhood of the Light> guild bank has 5"
"Total 11"
PvP
Capping: "Battleground timer mod with some extras"
Capping : WoWInterface Downloads : PvP/Arena/BattleGrounds
dgks (killshot notifier): "Notifies you when you get the killshot on another player. It also notifies others in the raid that you got the killshot. It does this by playing the Unreal Tournament sounds. ("Ownage!", "Killing Spree!", "Dominating!", "Unstoppable!", "Godlike!", and "Wicked Sick!")"
dgks - Addons - Curse
VanasKoS: "Kill-on-Sight notifier, that uses every possibility, to detect near KoS targets, and notifies the User in different ways. Additionally it records PvP-Stats in outdoor PvP and shows these in the tooltip (configurable). "
VanasKoS - Addons - Curse
I like this addon to note whom has ganked me
Raiding/Party
BossTactics: "Improves and simplifies explaining boss tactics in World of Warcraft."
"* Tactics for all Raidinstances ingame"
"* Maps for every bosslocation, to show where people have to stand"
BossTactics - Addons - Curse BossTactics Addon - About this Addon
NOTE: This isn't quite ready for Wrath raids yet as of this writing, but the authors note that they are working on it. I see lots of potential for this based on the screenshots of older raids. VERY exciting to me
HeadCount: "Tracks raid attendance, loot, and boss kills."
HeadCount - Addons - Curse
Not necessarily for DKP, but is useful as a tracking system IMHO.
Heal Organizer: "Helps organizing the healers in your raid by allowing the user to drag and drop healers into different assignments. Assignments can be as complex or simple as the user wishes."
Heal Organizer - Addons - Curse
See also: SurgeonGeneral (below)
ReadyCheckAnnouncer: "Announces results of readychecks to the raid/party,
installs "/rc" alias, shows rc timer bar."
ReadyCheckAnnouncer - Addons - Curse
Self explanatory
SurgeonGeneral: "Simplify healing assignments in a raid situation. It's easy to use interface allows you to give all your healers assignments and then report those assignments to /raid and/or the custom channel of your choosing. It supports multiple phases for complex fights.""
SurgeonGeneral - Addons - Curse
See also: Heal Organizer (above)