Shamens in World of Warcraft have always been able to enchant their melee weapons with special imbues. So far these enchants had different effects when used with a melee attack, like, for example, additional attacks from Windfury Weapon, or a slowing effect from Frostbrand. This made most of these enchants only interesting for Enhancement Shamans, as other specs were rarely hitting something with their weapon. The enhancement Shaman only used Windfury though, as that was the most effective enchant. Elemental and Restoration Schamans used Weapon Oils instead, that increased the healing or spellpower of their weapons.
Wrath of the Lich King changed this: Weapon oils were removed from the game more or less, as they can no longer be applied to weapons above level 70, and the Shaman's weapon enchants were changed, so they would be useful to every spec. Flametongue Weapon now increases the Shaman's spellpower and, with the help of a glyph, his critical strike chance, making it the first choice for Elemental Shamans.
Earthliving Weapon has become the primary weapon enchant for Restoration Shamans. Its primary effect is an increase of the Shaman's healing spellpower. The secondary effect is the chance of leaving a heal over time effect on every target that has been healed. Some Shamans even try to maximize this secondary effect by speccing into dual wield, doubling the chance for this Earthliving effect to occur as both weapons are enchanted with Earthliving Weapon then. Enhancement Shamans stay true to their old Windfury Weapon. While was was enchanted on both weapons in the Burning Crusade it is now possible to use a fast off-hand with Falmetongue Weapon. An effective way of boosting the new Lava Leash.