The axe, the myth, the legend:

So they've datamined Shadowmourne's legendary version off the PTR, here is what we have in all it's glory:

Shadowmourne

Binds when picked up

Unique

Axe

Two-Hand

Speed 3.70

954 - 1592 Damage

(344.1 damage per second)

+198 Stamina

+223 Strength

Red Socket

Red Socket

Red Socket

Socket Bonus: +8 Strength

Classes: Warrior, Paladin, Death Knight

Durability 145 / 145

Requires Level 80

Item Level 284

Equip: Improves critical strike rating by 114.

Equip: Increases your armor penetration rating by 114.

Your weapon swings have a chance to drain a Soul Fragment granting you 40 strength. When you have acquired 10 Soul Fragments you will unleash Chaos Bane, dealing 1900 to 2100 shadow damage split between all enemies within 8 yards.

Pretty much speaks for itself. This is the endgame of all endgame's for Plate DPS. The 3.7 Swing Speed ensures some beefy hits on all your instant attacks. The red slots scream "socket me with dps gems" And the unique proc is now better than ever. The undead clause is gone, and a straight strength gain for each shard is just godly good. You don't even have to ask who gets the weapon as it's slapped right on there for reminder. It's not a hunter stat-stick, it's not the rebirth of Enhancement 2h, this is strictly a plate 2 hander. That of course brings up the question of it'll work as a tanking axe for the Death Knight community.

You can look at the stats and see that yes, everything you need to tank with is on there: Strength for parry, a great chunk of stam, slow swing speed to avoid parry gibbing, gem slots for what have you. So yes, it'll work as a tank weapon. It is a supreme waste to use it as such though. Raid members who dps at the top of their game and have the talents to maximize the effectiveness of the weapon is what this thing is for. The armor pen on the weapon speaks more usefulness to Warriors more than Death Knights and Paladins, but armor pen is still a dps increase for all the classes listed above.

In short, give it to your highest plate dps, where it's going to have the most usage.

Of course, we're still not entirely sure how you "give" this weapon, as starting details of the quest have yet to be unveiled. We know that you you'll end up turning Arthas' old hammer into the progenitor of the legend, but what starts the quest has yet to be determined.

Another interesting note with the quest for the legendary axe is that parts of the quest line, at least on the ptr, have noted acquiring certain elements from ending bosses of each wing of Icecrown. Coupled with the delayed lockout that was recently announced, don't expect to see this baby in the hands of hardcore raiders until after quite some time.

P.S. I ever see anybody socket this thing with an AP gem, I will hunt you down!