Update 5:30pm EST: I reached Blizzard Entertainment and this is the official response. Our IncGamers main website is echoing the same official response:

Blizzard Quote:
Blizzard Entertainment has not announced any details about the next BlizzCon. We recommend that players refrain from making any BlizzCon-related travel plans at this time.

Update 4:44pm EST: Within a few minutes, the page no longer exists. It has been removed. I took video of my monitor to show you the page, and what happened after I reloaded the page. Will put the video up sometime later.

Original Story 4:22pm EST: The Anaheim Convention Center in California has been the official stage in the past years for the Blizzard Entertainment mega-convention known as Blizzcon. Last year the Anaheim Convention Center welcomed over 25,000 players who traveled from all around the world to meet the Blizzard Entertainment developers, play Starcraft II and Diablo III demos, and to hear what the new World of Warcraft expansion [Cataclysm] was all about.

A few months ago, there was a massive response to the rumor that BlizzCon 2010 would take place at Las Vegas. The Las Vegas Convention Center quickly responded it had been a misunderstanding and the page should never have gone online, as it was a placeholder that was never confirmed or secured by Blizzard Entertainment.

Eldorian (Blizzplanet) has discovered something of interest. The Anaheim Convention Center had not shown any schedules for Blizzcon on its official website up to this point. Now the website currently lists Blizzcon to happen on October 22-23, 2010.

This however, might not be a final date so don’t jump on your horses with this to book flight and hotel reservations just yet. We will have to wait for an official response from Blizzard Entertainment. There is a chance this is another placeholder or automatic renewal that shouldn’t have appeared online. There’s no guarantee that a BlizzCon might be held this year. However, there’s still one more Diablo III Class to be unveiled. There’s no better place to announce this new class than at BlizzCon or at the Blizzard Worldwide Invitationals. None of these events have been confirmed or announced by Blizzard Entertainment as of the time of this post.

Starcraft II might be in beta by the time BlizzCon takes place, and the showcasing of World of Warcraft: Cataclysm’s latest demo is a no brainer. Could there be an announcement of the Next-Gen MMO or the new IP this BlizzCon?