Primal Strike is a new shaman ability that comes with Cataclysm, learned at level 3 for 60. It was first announced in the Cataclysm shaman preview.
Primal Strike is a new weapon-based attack that every shaman will learn very early in the game. The goal with this ability is to make leveling as Enhancement rather than as Elemental more viable, since many key Enhancement talents become available at fairly high levels. Like claw for feral cat druids and sunder armor, Primal Strike will be replaced at higher levels by a talent in the appropriate tree (namely [Stormstrike]).