Can deal a huge amount of damage when multiple targets are within range.
Can be used for removing snares and roots and making you immune to most forms of crowd control.
Can be used if low on rage to maintain DPS while regenerating it.
Can be used to instantly dispatch any number of low level enemies.
Tips and tactics
Warriors in Bladestorm can only be stopped if killed.
When snared or rooted, Bladestorm can be used to stay on your opponent, as well as dealing respectable single-target damage. It can also be used as a defence against incoming crowd control effects such as [Polymorph].
You cannot use any other abilities during Bladestorm. This can make it very easy for some classes to escape you, without fear of [Charge], and prevents you from interrupting using abilities such as [Pummel]. If needing to interrupt healers or chase ranged types, consider not using Bladestorm. You can also cancel Bladestorm prematurely by right-clicking the buff, or by using the following macro:
/cancelaura Bladestorm
Bladestorm does stack with warrior buffs and abilities such as [Recklessness]. This ability must be triggered before using Bladestorm.
Since warriors in Bladestorm usually deal a lot of damage, and cannot use any other abilities, Bladestorm often generates a large amount of rage. Choosing to Bladestorm when you are already low on rage is ideal, preventing your DPS from dropping and getting maximum benefit from the ability. Burning spare rage with abilities such as [Heroic Strike] before Bladestorming can allow you to minimise rage wastage.
Bladestorm can be used while charging, jumping or falling. Since Bladestorm's first whirlwind is performed instantly, be sure not to waste any of its duration while still out of range of your targets.
Warriors still deal normal auto-attacks while Bladestorming.
Fury warriors attack with both weapons during Bladestorm.
Defence against Bladestorm
Bladestorm has a number of weaknesses:
The warrior is unable to use any other abilities during Bladestorm, such as [Charge] or [Pummel]. Abilities such as [Blink] and [Disengage] can make Bladestorm worthless if timed correctly.
Bladestorm's damage output is most effective against groups of enemies. When in groups, prevent this by running in different directions. The warrior will have to choose a single target to chase, at most dealing a fraction of the ability's potential damage and largely wasting the cooldown.
Trivia
The unusual description of the old version ("you do not feel pity or remorse or fear and you cannot be stopped unless killed") is a reference to the 1984 film The Terminator.
Cooldown has decreased to 60 seconds (down from 1.5 minutes).
Arms: Bladestorm now deals 180% of weapon damage (up from 120%).
Protection: Bladestorm now deals 160% of weapon damage (down from 240%).
Patch 5.2.0 (2013-03-05): Now provides immunity to Disarm while active.
Patch 5.0.4 (2012-08-28): Now available for all specializations as a talent. Weapon damage reduced from 150% to 120%. Enables the warrior to dodge, block and parry for the duration but only perform Shout abilities.
Hotfix (2011-12-02):Bladestorm will now always grant immunity when it is cast.
Hotfix (2010-12-21):Bladestorm now deals 150% normalized weapon damage as advertised. It was incorrectly dealing 100% normalized weapon damage.