• Stormrune Edge
• Item Level 232Disenchants into:
  [Abyss Crystal]: 1-2
• Binds when picked up
  
• Sword
• Two-Hand
  
• Speed 3.40
• 632 - 949 Damage
• (232.5 damage per second)
• +121 Agility
  +120 Stamina
• Durability 120 / 120
• Requires Level 80
• Equip: Improves critical strike rating by 86.
  Equip: Increases attack power by 160.
  Equip: Increases your armor penetration rating by 70.
• 
• Sell Price: 29 49 39

Source

This item drops from Assembly of Iron in the 25-man version of Ulduar.

Patch changes

• Patch 3.2.0 (04-Aug-2009): Renamed from Rune Edge 
  
• Patch 3.1.0 (14-Apr-2009): Added. 
  

External links

• Battle.net (EU)
• Wowhead
• Thottbot
• WoWDB