Blizzard reveals that the upcoming add-on for their real-time strategy, StarCraft 2. According to the game's official web site, StarCraft 2: Heart of the Swarm is going to be out on March 12, 2013.

Here's a bit more about the story in Heart of the Swarm:

The Queen of Blades is gone. On the hellish planet Char, Jim Raynor harnessed the power of an ancient Xel'Naga artifact in a desperate bid to stop the zerg Swarm from overrunning the Koprulu sector, and the artifact restored Sarah Kerrigan to her human form. Without their queen to guide and unify them, the Swarm has fractured into several broods scattered throughout the Koprulu sector. One of the greatest threats to the galaxy has been neutralized... or so it seems.

Sarah Kerrigan is on the loose. Even without the terrible powers of the Queen of Blades or the might of the Swarm at her command, the former Ghost remains a foe not to be taken lightly. But if the artifact really did set her free, then why is Kerrigan seeking out zerg broods scattered throughout the Koprulu sector? What happened to Jim Raynor? Is she still pursuing her quest for vengeance, or has her transformation given Kerrigan a new purpose?

Man, they sure are taking their sweet old time with this one.