As of writing this nothing has been confirmed by Blizzard. An ex-blizzard employee has released video and screenshots of what looks like the Diablo 3 Beta.
A user on Reddit has posted video and screenshots of the highly anticipated Diablo 3 Beta. In previous posts this user claimed to be an ex-employee of Blizzard Entertainment.This seems to be the real deal which would lead people to believe the beta will be coming soon.
Below is the video along with a gallery of images.