No date D:
Bashiok said:That's weird, they originally had the exact quote in their Inferno article and then pulled it out and only quoted "When it's ready." in that new mini-blip thing. I think his original quote on Kotaku was "by the end of September" but I didn't copy it down.
Anyway, to set expectations straight, beta in August is unlikely. But it shouldn't be too long after.