the 2012 Battle.net World Championship, a major global eSports event to take place in Asia before the end of this year, though exact details on the event's timing and location are not being supplied at this time. As a result, the next BlizzCon convention will not be held until 2013, as they say:
We’re excited to be showcasing Blizzard eSports on a truly global stage this year. We're also heavily focused on getting Diablo III, Mists of Pandaria, and Heart of the Swarm into players’ hands as soon as possible. In light of our jam-packed schedule, we’ve decided to hold the next BlizzCon in 2013.