StarCraft II: Heart of the Swarm Intro and Gameplay Trailers

Next chapter of Blizzard Entertainment’s StarCraft II saga introduces key new online features and continues the epic story of Kerrigan, Queen of Blades
Blizzard Entertainment has released the intro video for StarCraft II: Heart of the Swarm, the first expansion to Blizzard's real-time strategy game StarCraft II: Wings of Liberty set to be launched in stores and online on March 12, 2013. Heart of the Swarm features a new campaign continuing the epic story of Sarah Kerrigan, Queen of Blades, as she gathers the remnants of the zerg Swarm and plots her revenge against the treacherous dictator of the Koprulu sector, Arcturus Mengsk. It also introduces several new multiplayer units and features that enhance the acclaimed StarCraft II online experience.
Update: a gameplay movie is also available.