Blizzard may not have an "official" release window for Starcraft 2: Heart of the Swarm, but don't expect it to occur in 2011.SC2 Lead Producer Chris Sigaty told IGN the company would be "very hard pressed to bring [Heart of the Swarm] out next year." He noted that there is no release date, but because the sequel-spansion is more ambitious than Warcraft 3: The Frozen Throne was to its core game, he doesn't "anticipate it being done in that one year time frame."
Sigaty's words are in the same vein as those of Battle.net project director, Greg Canessa, who implied the game would have an early 2012 launch. So, for those still holding out hope for a 2011 release for Heart of the Swarm, just keep on weaning that dream