analysis of his statement can be found here and elsewhere.
One part caught my attention:
"We view it as our role in the system to constantly be innovating and be
updating what our system is to reflect what the current social norms are."
Can and do social norms change over a period of 5-6 years? (Zukerberg argues that was he starting facebook today, they would have gone with the privacy-off default that they set now for various bits of personal information).
The article linked to raises some interesting questions, suggesting that it looks like facebook has pulled a 'bait-and-switch'. Getting users used-to and comfortable-with sharing data within a private setting (or one that looked private, or at least corralled into certain social settings - e.g. colleges) before opening it out to an open fully searchable setting that offers to make more profit for the company (by leveraging the personal data it holds).
I'm not sure that social norms could change over this period, if that is understood as values and expectations. What could however change is habits, which are a bit more amenable to unconcious alteration.
The article also makes (I think) a mistake in assuming that users went onto facebook 1) assuming it was secure, and 2) making a decion about how private it was before joining, assessing that risk whilst in full possession of the facts, and then decided to join or not. From the focus groups we've been looking at, and some personal experience, it all looks a lot fuzzier.
Mike Zimmer has a good take on this statement, simply that it's not surprising, not new, and now true. Read it on his blog here