This stunning fist (geeky pun intended, of course) is wielded by the Warchief at the top of Hellfire Citadel. And you've got to fell him (after fighting through his clan) to get it.

Name: The Bladefist
Type: Epic Main Hand Fist
Damage/Speed: 152-283 / 2.60 (83.7 DPS)
Abilities:

• Chance on Hit: Increases your haste rating by 180 for 10 seconds.
• At level 70, that means an increase in speed of ~17% when it procs, which according to reports, is fairly often. (Procs per minute involves a lot of math, and regular readers will know I'm terrible at getting math right, but from what I understand, this thing hits at 3 PPM, halfway between Crusader (1), and Lifestealing (6). So pretty often, but not every time.)
• Also, I'm told the Mongoose enchant can stack with this ability, which means if you've got both going, it's a lot of slashy slashy and stabby stabby (technical terms).
• Unfortunately, this baby is Unique (not to mention Main Hand), so no, you can't dual wield them like Kargath does.

How to Get It: To answer that, we have to go back a little bit in Warcraft Lore. Kargath Bladefist wasn't always warchief of the Shattered Hand clan, and he wasn't always known as the Bladefist. When he reached the level of grunt, the dude cut off his own hand, and replaced it with this weapon. And anyone badass enough to do that should definitely be Warchief, so he rose through the ranks and took over Shattered Halls. There's more to it than that (maybe we'll see a KYL someday on him), but that's what this weapon is all about.

And you know taking it away from him is not going to be an easy task. You've got to storm into Shattered Halls (which means you've got to get the key, which is a nice quest chain in itself), and you've got to do it on Heroic mode. Make your way through the Gauntlet, past the stupid Ogre (I'm just kidding, he's awesome), and all those damn assassins (they are not), and then topple the Warchief himself. Pull this bad boy from his wrist (it drops at around 5%), and it's yours. Impressive, no?

Getting Rid of It: I don't know why I ever decided to include this section. Why would you want to get rid of any of this phat loot? A vendor will give you 10g 46s 29c for it, and it will disenchant into a Void Crystal.