Blizzard began selling BlizzCon tickets at 1:00 PM by 1:02, the queue was around 20,000 people (i.e. likely sold out).
I kept refreshing at 12:59 PM and got in once it hit 1:00 PM and I was still 600th in queue. So just a FYI for people looking to purchase tickets in the future, you need to be on the site immediately or you will lose out.