Corrupted Mooncloth

Vengeful Gladiator's Mooncloth Hood Priest-only PvP reward.
Merciless Gladiator's Mooncloth Mantle Priest-only PvP reward.  The token to buy it drops from Void Weaver in The Eye.  ** Update 11/22/2013:  Not sure when this changed, but you can now buy this from Kezzik the Striker in Area 52 in Netherstorm for 750 Honor.  **
Raiments of the Corrupted Drops in Ulduar 10
Binding of the Dragon Matriarch Drops in Ulduar 10
Pulsar Gloves Drops in Ulduar 10
Royal Boots Green BOE
Tower of the Mouldering Corpse Drops in the Forge of Souls
Deathchill Cloak Made by Tailors.  There are a few other cloaks with the same appearance.

Details here.

Sun-Infused Sin'dorei

Circlet of Prophecy Priest Tier 1.  There are lookalikes--check Wowhead.
Flarecore Mantle Made by tailors.  Requires Thorium Brotherhood rep to buy the pattern.
Scarlet Sin'dorei Robes Drops in heroic Magister's Terrace.
Girdle of Ruination Made by tailors.  Pattern is a world drop.
Imperial Red Gloves Green BOE
Imperial Red Boots Green BOE
Perdition's Blade Drops in Molten Core.
Flametongue Seal Bought for Justice Points in Shattrath.

Alternate versions

Whitemend Hood Made by tailors.
Primal Mooncloth Shoulders Made by tailors.
Girdle of Prophecy Priest Tier 1
Sun-Infused Focus Staff Drops in Magister's Terrace.  The green BOE Frenzied Staff is another Blood Elf style staff.

Red Linen Sash Alliance only quest reward in Elwynn Forest.
Mantle of the Corrupted Drops in Naxx 25.
Lok'amir il Romathis Drops in Blackwing Lair.

All details here.

Hero's Acumen

Unfortunately, the Robes of Acumen are no longer obtainable.  I still have mine from a Maraudon run way back in Vanilla WOW.

Heroes' Shoulderpads of Faith Priest Tier 7.  Token Spaulders of the Lost Conqueror drops in Naxx 10.

Acumen Robes No longer available.  Used to be a quest reward from Maraudon.

Chillbane Belt Drops in Hour of Twilight.

Resplendent Bracelets Green BOE

Mystical Gloves Green BOE

Kurkenstoks Alliance-only quest reward on Azuremyst Isle.

Surgeon's Needle Dagger drops in heroic Pit of Saron.

Manual of the Nethermancer Drops in The Mechanar.  (Book of Blood and Stormbound Tome--both made by incription--have the same appearance.)

Alternate versions

Runecloth Shoulders Made by Tailors

Rod of the Sun King Mace drops in The Eye

Staff of Dominance Staff drops in Molten Core

All details here.

Changes to Scholomance in Mists of Pandaria

Be aware that with the release of Mists of Pandaria, there will be major changes to Scholomance, including elimination of the four minibosses before Darkmaster Gandling.  These minibosses drop pieces of the following sets, which presumably will no longer be available.

http://www.wowpedia.org/Scholomance_(Mists_of_Pandaria)

Necropile Raiment

Cadaverous Garb

Bloodmail Regalia

Deathbone Guardian

Icy Mooncloth

Here's a set based around the Mooncloth Robes for a Frost Mage or healy Priest.

Royal Headband Green BOE
Regal Mantle Green BOE
Mooncloth Robe Made by tailors
Ebonweave Gloves Made by tailors.  They are long enough that most bracers shouldn't show.
Mindfire Waistband Drops in the Blood Furnace
Staff of the Unknown Road Quest reward from Zul'Farrak
Regal Boots Green BOE

Alternate version

Underworld Mantle Drops in Ulduar 10 normal
Grand Magister's Staff of Torrents Drops in Sunwell Plateau

Alternate Shoulders

Khadgar's Shoulderpads of Triumph Alliance Mage Tier 9

Merciless Gladiator's Mooncloth Mantle Priest-only PvP reward.  The token to buy this drops from Void Reaver in the Eye.

Sanctified Crimson Acolyte Mantle Priest Tier 10

All details here.

Fire! Fire! Burning! Burning!

Put this set of mostly crafted items together for your favorite fire mage.

Elegant Circlet Green BOE

Cindercloth Robe Made by tailors

Red Mageweave Shoulders Made by tailors

Red Mageweave Gloves Made by tailors

Red Linen Sash Alliance-only quest reward from Elwynn Forest

Rod of the Blazing Light Drops in Heroic Magister's Terrace

Resplendent Cloak Green BOE

Details here.

Update 8/17/12:  added screenshots.