I was one of the Berkeley posters on GC. I received an email notice there was an update to my application, clicked the link, and had a letter of admission from the Vice Provost of Graduate Studies. It seemed to be a school-wide form letter, and said the department would follow up later with details on funding.
The acceptance appeared to me a little unusual, as the update came around 7-ish PST, well after business hours, with no separate acknowledgment from the department or faculty (which to my knowledge is standard). You guys are correct that last year, most UCs released decisions uniformly around March 8th.
Given the low number of posts on GC, (especially relative to the number who posted their acceptances to Stanford, of which I would assume there would be overlap) my intuition is that either this is a mistake, or they might be admitting in batches. At any rate, I would definitely not take the lack of an update to be an implicit rejection.