The Ashbringer  
The Ashbringer quest is currently incomplete, but this is our best guess....
First you must aquire the Corrupted Ashbringer from the undead Highlord Mograine in the Naxxramus Necropolis. You must then uncorrupt the sword using a holy place or some sort of holy item, possibly also aquired in Naxxramus.
Ashbringer
Binds when picked up
Unique
Two-Hand Two-Hand Sword
201 - 247 Damage  
+ 30 - 50 Holy Damage  
(88.0 Damage per second)  
Requires level 60  
Chance On Hit : Blasts a target for 700 Fire damage
"Blade of the Scarlet High Lord"
   
 
Atiesh, Greatstaff of the Guardian  
Atiesh is broken into 42 individual pieces. All the pieces must be collected in order to reform the staff. Then the staff must be exorcised in order to expell the evil taint of Sargeras from the staff.
Atiesh, Staff of the Guardian
Binds when picked up
Two-Hand Staff
130 - 244 damage
+ Stats, depending on class  
   
Requires level 60  
Equip : Different effects, depending on class
Equip : Different pary auras, depending on class
Use : Creates a portal, teleporting group memebers that use it to Karazhan.