So, given that only two Blizzard titles are officially targeted for 2012, Heart of the Swarm is the most likely to get delayed into 2013.
Source: http://investor.activision.com/releasedetail.cfm?ReleaseID=647732Activision said:The company's first quarter 2012 outlook does not incorporate a new release from Blizzard Entertainment, but its calendar year 2012 outlook anticipates two releases from Blizzard Entertainment.