Windfury Weapon

Windfury Weapon is a Shaman ability, learned at level 32 for.

Improvements

 * Elemental Weapons increases its effect by 40%.
 * Glyph of Windfury Weapon Increases the chance to proc by 2%

Tips
Windfury is the main enhancement shaman buff. It offers up to 40% damage increase to a shaman's base melee DPS (if wielding a single three second or slower weapon), not counting the attack power bonus granted on 2/7ths of all swings. As of 2.01, Windfury procs can trigger weapon-based procs and enchants—meaning one could potentially have a Crusader proc three times (the normal swing and the 2 Windfury occurrences) or 6 times if one is Dual-Wield Stormstrike spec'd. Windfury procs that crit will also trigger Flurry, but Windfury procs themselves do not consume Flurry. This means that after getting a high crit chance, one could have a never-ending Flurry buff, as unlikely as these situations are.

Slow weapons are recommended for Stormstriking shaman and for PvP in general, especially due to Stormstrike. This is because the damage added by Stormstrike and Windfury are not normalized, so the full amount of damage is dealt instead of being modified by weapon speed. Also, Windfury exists on a three second internal cooldown that would be wasted with faster weapons.

In PvE, Windfury should always be used for the main hand, for the benefit of spell power and improved Lava Lash damage from Flametongue is viable for the off-hand. As for PvP, one could easily mix-in Frostbrand Weapon to help keep the opponent in melee range, especially due to the Frozen Power talent. Dual Windfury Weapon will rapidly increase one's damage, of course, as the buff is that powerful. A common question in regards to PvP is whether to use a two-handed weapon or dual wielding. Either way, one should definitely be using Windfury. Two-handed weapons will provide the shaman with a large amount of burst damage, but due to resilience, as well as the potential "drought" of Windfury procs, it may be better to dual wield in favor of more consistent damage.