So, here were the big highlights of past Blizzcons.
I'm including the Worldwide Invitational as well, since it was the EU version of Blizzcon. (Note: There was no Blizzcon 2006, and WWI was cancelled in 2009 in favor of Blizzcon moving forwards.)
* Oct 2005 Blizzcon - World of Warcraft: The Burning Crusade Announced
* May 2007 Worldwide Inv - Starcraft 2 Announced
* Aug 2007 Blizzcon - World of Warcraft: Wrath of the Lich King Announced
* Jun 2008 Worldwide Inv - Diablo 3 Announced
* Oct 2008 Blizzcon - Starcraft 2 Trilogy Announced
* Aug 2009 Blizzcon - World of Warcraft: Catacylsm Announced
* Oct 2010 Blizzcon - Some guy in a red shirt asks a question
I hope this isn't going to be a trend.