It is unknown if this is in reference to internal F&F Closed Beta or external Closed Beta. Felicia Day acknowledged in her Twitter she just got a email invitation.

I don’t know about you, but if she really meant External Closed Beta, I am reloading my email like no tomorrow.

Felicia Day: “OH HAI DIABLO 3 BETA INVITE, YOU ARE PRETTY IN MY INBOX”

source: Felicia Day Twitter

Update: Heard from Eldorian, there was a second F&F beta invite wave. [Makes sad-panda face] That won’t discourage me from reloading my B.net account page though. =D

PS: Image by Emily Ibarra (ediphotoeye.com)