The official site for BlizzCon 2008 is now up. The launch prefaces the ticket sales for the event, scheduled for August 11. If you're considering going to the Anaheim, CA event, you can check out the website for all the information you need from hotel & travel accommodations to the various panels throughout the weekend. World of Warcraft-related panels include discussions on class design, PvP, WoW art, dungeons & raids, and UI & mods.
The event, the first BlizzCon to be televised live, will also see the finals of the Global Arena tournament. Even if you're not interested in Arena PvP, there are a bunch of other contests you can participate in (or watch for your amusement), such as the ever-popular costume contest, dance contest, and even the machinima competition. Details aren't up on the site yet, but you can bug them on their FAQ about that.