A beta has been running for a few months already (edit: since September 2011). You can sign-up for it (although I assume it is way too late for that now) on your battle.net settings page.
I think he's ramblin' off on a joke regarding how reddit.com/r/diablo took every single ounce of change in regards to Diablo as a "sign of the beta" or more recently "sign of release date".
If twitter of any blizz guy was updated? SIgn of the beta. New picture on the website? Sign of the beta. A sneeze came from 4th floor blizzard HQ? Sign of the beta.
If twitter of any blizz guy was updated? SIgn of the beta. New picture on the website? Sign of the beta. A sneeze came from 4th floor blizzard HQ? Sign of the beta.