World of Warcraft: Warlords of Draenor's beta has begun
"Over the course of the test, we'll be inviting community veterans, press, fansites, friends and family, and opt-in beta testers to participate," Blizzard said.
The current phase of the beta test focuses on the Tanaan Jungle starting experience. It'll allow Alliance to continue into Shadowmoon Valley, while Horde can check out Frostfire Ridge. Blizzard also said that high-level content will become available for testing in future updates. Additionally, level-90 character templates are available in case you want to try out a new character. Alternatively, you can just copy over your own high-level characters.
The beta for Warlords of Draenor isn't under NDA, so I'm sure you'll see lots of screenshots and videos in the coming days. "Please keep in mind that the expansion is still in development," Blizzard noted. "We'll be making changes to the game as the beta evolves, and what you'll see during the beta test is not necessarily representative of the final game."
To opt in to the Warlords of Draenor beta, you must have a Battle.net account with at least one Blizzard game attached to it. You'll then be able to opt in from the Beta Profile page.