As one of the loots in the Kil'jaeden, I have caught glimpse of it as early as in the downfall of the sun well. Now after some conclusion I will introduce it as followings:
Name: Golden Staff of the Sin'dorei
Type: Epic Two-hand Staff
Damage/Speed: 146-338 / 3.20 (75.6 DPS)
Abilities: +60 Stamina, +54 Intellects, +57 Spirit.
Durability: +120/120
Red and two Blue sockets, nicely fitted with some +22 healing gems and/or +10 Spirit gems and you're talking about some real power. +4 Spirit socket bonus.
The required level is level 70.
Improves spell haste rating by 32 and increases healing done by up to 550 healing, and damage done by up to 183. Not since right before the last expansion has there been a staff this nice in comparison to other gear, and even if you could match the healing on a one-hand/offhand combo, as long as you get the right gear and enchants together, the Spirit bonuses on this baby are going to give that duo a run for the money. Take a good look, because this is the kind of stuff that's going to be dropping in endgame raids at level 80.
Sin'dorei, in other words, we can call it Blood Elves, or "children of the Blood" in Thalassian. And yes, the staff looks just like the one in the BC art, as seen above. This is very BC staff, if not the most defining staff of this expansion. Look for a lot less gold and green and a lot more blue and black in Wrath of the Lich King.
Since it is one item belong to Kil'jaeden, it drops from the last boss currently in the game. And since we've seen so few drops from Killy Jay so far, we're not sure of the drop rate at all.
You can drool, though. And in ten levels, when we're all working through Naxx again, maybe you can convince your raid to go back and help you get it.
As for how to sell them, you can sell it to vendors for 20 WOW gold or and disenchants into a Void Crystal.