StarCraft 2: Heart of the Swarm, the first expansion to StarCraft 2, won't launch this year — developer Blizzard Entertainment is now aiming to release it in the "first half [of] 2013," Blizzard chief executive Mike Morhaime revealed during an Activision investor call this afternoon.

The studio has been beta-testing the expansion since early September, and according to Morhaime, "the development team has been collecting great feedback from the community." Until now, fans had held out hope that the expansion would launch this year, but Morhaime said, "We're working hard towards a first half 2013 launch for Heart of the Swarm."

Asked to provide a more specific window, Morhaime demurred, saying it's "too early" right now.

"As with all Blizzard games, our ultimate goal is to provide the best possible experience for our players," said Morhaime, "and we will take as much time as is needed to ensure that Heart of the Swarm meets the expectations of our players, as well as our own high standards."

According to Activision, more than 6 million copies of StarCraft 2: Wings of Liberty have been sold since the game's launch in July 2010.