"Supposedly, the Beta will go live by September 30th, as long as there are no major delays. I’m going to BlizzHQ on Wednesday to playtest the Beta, as part of a press event as well… I think we’re almost there... If all goes well within the Beta, it’s very possible to have a 2011 release."
Sixen then stated that an upcoming Activision Blizzard Second Quarter Calendar 2011 Results Conference Call will officially announced the beta date, "The conference call is on August 3rd, they won’t announce any information on the Collector’s Edition, nor for preorders. However, they may release information on the D3 Beta. (In my opinion), they’ll tell us information about the beta at the Conference Call."
This comes on the heels of some very unfavorable announcements by Blizzard that there will be no off-line gameplay or modding in Diablo III.