Shade Feats

Binding Shadow
Prerequisites: Shade, wizard, Tome of Binding class feature
Benefit: When you use your Tome of Binding with an arcane summoning power that also has the shadow keyword, you can use your Charisma modifier instead of your Constitution modifier.
    In addition, when you use your Tome of Binding, all creatures summoned by the arcane summoning power you are using gain partial concealment until the end of your next turn.

Brooding Leader
Prerequisites: Shade, warlord
Benefit: You and any ally within 10 squares of you who can see and hear you gain a +2 bonus to Arcana checks and Stealth checks.
Special: If you are a shade, you can select this feat in place of the Combat Leader class feature. 

Cimmerian Cunning
Prerequisites: Shade, bard, Virtue of Cunning class feature
Benefit: Whenever you use Virtue of Cunning to slide an ally to a square that grants any cover or concealment, that ally can make a Stealth check to hide as a free action.

Concealed Mettle
Prerequisites: Shade, paladin, divine mettle power
Benefit: Whenever you use Virtue of Cunning to slide an ally to a square that grants any cover or concealment, that ally can make a Stealth check to hide as a free action.

Concealed Virtue
Prerequisites: Shade, bard, Bardic Virtue class feature
Benefit: Whenever you would normally grant an ally the benefit of your Bardic Virtue, you can forgo granting that benefit to instead grant the ally partial concealment until the end of his or her next turn.

Concealing Covenant
Prerequisites: Shade, invoker, Divine Covenant class feature
Benefit: When you use a divine encounter or daily attack power on your turn, you can forgo gaining the normal benefit of your Covenant Manifestation to instead grant an ally within 10 squares of you partial concealment until the end of his or her next turn.

Concealing Resurgence
Prerequisites: Shade, warden, Guardian Might class feature
Benefit: When you use your second wind, you gain partial concealment until the end of your next turn.

Covert Presence
Prerequisites: Shade, warlord, Commanding Presence class feature
Benefit: When an ally who can see you spends an action point to take an extra action, that ally gains partial concealment until the end of his or her next turn.

Dark Eruption
Prerequisites: Shade, ardent, Mantle of Impulsiveness class feature
Benefit: When you use ardent eruption, each target gains concealment until the start of your next turn.

Deceptive Shadow
Prerequisites: Shade, wizard, Orb of Deception class feature
Benefit: You can use your Orb of Deception when you miss with any arcane power that has the shadow keyword.
    In addition, whenever you use Orb of Deception to repeat an attack, each square within the area of the new attack becomes a zone of dim light that lasts until the end of your next turn.

Enshrouding Surprise
Prerequisites: Shade, rogue, Sneak Attack class feature
Benefit: When you deal extra damage to an enemy using Sneak Attack, that enemy treats creatures more than 2 squares away from it as having partial concealment until the end of your next turn.

Enshrouding Twist
Prerequisites: Shade, Prime Shot, Prime Strike, or Shadow Twist class feature
Benefit: When you hit an enemy against whom you received a bonus from Prime Shot, Prime Strike, or Shadow Twist, that enemy treats creatures more than 2 squares away from it as having partial concealment until the end of your next turn.

Fading Boon
Prerequisites: Shade, warlock, one with shadow racial power, Pact Boon class feature
Benefit: When you reduce an enemy to 0 hit points, you can forgo using the power granted by your pact boon to instead use one with shadow as a free action.

Fading Enmity
Prerequisites: Shade, avenger, one with shadow racial power, oath of enmity power
Benefit: When you reduce your oath of enemy target to 0 hit points, you can use one with shadow as a minor action.

Fading Gloom
Prerequisites: Shade, one with shadow racial power, Psionic Augmentation class feature
Benefit: The first time you drop to 0 power points during an encounter, you can use one with shadow as a minor action.
    Also, while you have no power points remaining, you gain a +2 bonus to Stealth checks.

Furtive Knave
Prerequisites: Shade, rogue, First Strike class feature
Benefit: While you are hidden or invisible, you gain combat advantage against any enemy that has not yet acted during the current encounter.

Furtive Occultist
Prerequisites: Shade, warlock, Warlock's Curse class feature
Benefit: While you are hidden or invisible, you gain combat advantage against any enemies you have cursed.

Furtive Stalker
Prerequisites: Shade, ranger, Hunter's Quarry class feature
Benefit: While you are hidden or invisible, you have combat advantage against your quarry.

Furtive Vindicator
Prerequisites: Shade, avenger, oath of enmity power
Benefit: While you are hidden or invisible, you gain combat advantage against your oath of enmity target.

Gloaming Aegis
Prerequisites: Shade, swordmage, Swordmage Aegis class feature
Benefit: Whenever the target of your Swordmage Aegis hits one of your allies with an attack that doesn't include you as a target, that ally gains total concealment against the target until the end of the target's next turn.

Hidden Fragment
Prerequisites: Shade, psion, Shaper Focus class feature
Benefit: When you use shaped consciousness, the fragment is invisible to all your enemies until the end of your next turn. The fragment has a Stealth check bonus equal to your Stealth check bonus.
    Also, you can sustain the fragment's invisibility as a minor action.

Imposing Shadow
Prerequisites: Shade, wizard, Orb of Imposition class feature
Benefit: When you use your Orb of Imposition to designate a creature that is subject to one of your arcane powers that has the shadow keyword, you can use your Charisma modifier instead of your Wisdom modifier.
    In addition, when you extend the duration of an effect created by an arcane at-will power that has the shadow keyword, the effect lasts one additional turn.

Inumbrate Sneak
Prerequisites: Shade, rogue, Cunning Sneak class feature
Benefit: You gain the benefit of Cunning Sneak if the only cover you have is provided by intervening allies.

Manipulative Guardian
Prerequisites: Shade, fighter, battle guardian power or Combat Challenge class feature
Benefit: Whenever you hit an enemy with a melee basic attack granted by battle guardian or Combat Challenge, that enemy grants combat advantage to you until the end of your next turn.

Manipulative Ravager
Prerequisites: Shade, barbarian, Feral Might class feature
Benefit: When you first bloody an enemy during an encounter, that enemy grants combat advantage to you until the end of your next turn.

Nebulous Illusion
Prerequisites: Shade, wizard, Illusion Apprentice class feature
Benefit: Whenever you use an arcane illusion power, you can choose for the attack to deal necrotic damage in addition to the normal damage type.

Obscuring Aura
Prerequisites: Shade, defender role, one with shadow racial power
Benefit: While an enemy is marked by you or subject to your defender aura, it takes a -5 penalty to Perception checks made against your allies.

Protective Shadows
Prerequisites: Shade, leader role, one with shadow racial power
Benefit: When you use one with shadow, you can choose to grant the benefit to an adjacent ally instead of to yourself. If you do so, the benefit lasts until the end of the ally's next turn.

Sacred Shadows
Prerequisites: Shade, leader role, one with shadow racial power
Benefit: When you use one with shadow, choose on ally you can see. That ally gains temporary hit points equal to your Wisdom or Charisma modifier.

Shadow Dodge
Prerequisites: Shade, rogue, Artful Dodger class feature
Benefit: The first time during a round that an enemy misses you with an opportunity attack, you can teleport 1 square as a free action.

Shadow Shape
Prerequisites: Shade, druid, wild shape power
Benefit: You can use one with shadow and shade utility powers while you are in beast form.
    In addition, you gain a +2 bonus to Stealth checks while you are in beast form, 

Shadow Storm
Prerequisites: Shade, sorcerer, Storm Magic class feature
Benefit: Whenever you gain the benefit of Storm Soul, you also gain a +2 bonus to Stealth checks until the end of your next turn.
    Also, whenever you gain the benefit of Storm's Embrace, you become insubstantial until the end of your next turn.

Swirling Spiral
Prerequisites: Shade, warlock, one with shadow racial power, Darkspiral Aura class feature
Benefit: Whenever you deal 12 damage or more with your Darkspiral Aura, you can use one with shadow as a minor action.

Tenebrous Mantle
Prerequisites: Shade, ardent, one with shadow racial power, Ardent Mantle class feature
Benefit: Allies within the radius of your Ardent Mantle gain a +2 bonus to Stealth checks. When you use one with shadow, you can spend 1 power point to increase this bonus to +5 until the end of your next turn.

I think the real problem is the lack of racial traits. When compared to the eladrin, for example, this seems pretty obvious:

Eladrin Education / Practiced Sneak (weaker for the shade, since eladrin can choose any skill, while shades can only choose Stealth)
Eladrin Weapon Proficiency / nothing
Eladrin Will / nothing
Fey Origin / Shadow Origin
Trance / nothing
Fey Step / One with Shadow
Eladrin Racial Utility Powers / Master of Shadows

Here are a a few ideas for additional shade racial traits. The first is obviously based on Eladrin Will, while the other two are inspired by the 3.5E shade. If a DM isn't happy to allow these as racial traits, they can easily be taken as feats instead.

Umbral Infusion: You gain a +1 racial bonus to your Fortitude defense.
    In addition, you gain a +5 racial bonus to saving throws against illusion effects.

Veiled Haste: Whenever you begin your turn in a square of dim light or darkness, your speed increases by 2 until the end of your turn.

Twilight Healing: While you are in a square of dim light or darkness, whenever you spend a healing surge you regain a number of additional hit points equal to your Charisma modifier.

I've updated the first post with a number of additional feats (the total is now 34!), and also provided a link for a compiled .doc file containing all the feats plus the additional racial traits proposed above.

I've just checked out the new Book of Vile Darkness feats on the Compendium, and Disciple of Darkness is an excellent fit both thematically and mechanically with the feats and additional racial traits above .