Here are the list of raid auras and what they do, you can also find them in server updates but well this post is pretty old (14 Sept 10) so i figured i would help yall out.
Aura of the Stronghold
(Group Based)
+5% Melee Mitigation
+550 AC
+1300 HP
Aura of the Mighty
(Group Based)
+5% Minimum Melee Damage
+5% Maximum Melee Damage
+Proc: Strike of the Mighty Ones: 350 Life Tap that heals your group
Aura of the Witchdoctor
(Group Based)
+8% Innate Divine Intervention
+1300 Mana
+30 Mana Regeneration
Aura of the Bloodmage
(Group Based)
+5% Spell Damage
+5% Dot Critical Chance
+1300 Mana
+Spell Proc: Bloodmage Strike: 350DD Nuke
Aura of the Death Bringer
(AoE Based)
+5% Minimum Melee Damage
+5% Maximum Melee Damage
+550 AC
+1300 HP
Aura of the Glyph Bearer
(AoE Based)
+5% Spell Damage
+5% Dot Critical Chance
+10% Spell Haste
+1300 Mana
+10 Mana Regeneration