The BlizzCon website has word that the batch of BlizzCon 2013 tickets that went on sale last night has sold out. Your next opportunity to get a ducat for the show will be Saturday:

The first batch of BlizzCon 2013 tickets are sold out!

If you weren't able to get tickets this time, you'll have another chance on Saturday, April 27 at 10 a.m. PDT, when a second batch goes on sale. In addition, tickets to a special pre-BlizzCon dinner to benefit Children's Hospital of Orange County will go on sale Wednesday, May 1 at 7 p.m. PDT. In-depth coverage of BlizzCon will also be available through the BlizzCon Virtual Ticket. Keep an eye on BlizzCon site for more details in the near future.