Earlier this week, it was discovered that Blizzard Entertainment had trademarked "Warlords of Draenor." Believed to be the name of the name of the new World of Warcraft expansion, Blizzard practically spoiled the announcement when the pre-stream footage for BlizzCon 2013 (happening today) revealed a Warlords of Draenor expansion in the background.
We don't know anything about the assumed expansion, but after another quarter of losing subscribers, it's clear that World of Warcraft can use a boost. When Mists of Pandaria was release in October 2012 subscriptions were temporarily boosted, but that was short-lived.
Blizzard has yet to formally announce the expansion, but the WoW session begins at 3:30pm EST. If you have a virtual ticket you can watch it via stream. If not, keep it tuned to GameZone.