I heard a piece on NPR's Morning Edition earlier this week on 911 conspiracy theories. They interviewed Dylan Avery who made Loose Change, studiously avoiding talking about the evidence. Then they had on a researcher for the 911 Commission who dismissed skeptics by the old "the government is not that competent, too many people would have to know" etc. And that was that.
But they did address the issue. So definitely it is damage control.
But I thought something else might have been going on in addition. Since the poll came out saying 35% of people do not believe the government's story and the internet will keep that figure at least that high, I think they have decided that 911 is old enough that a certain amount of skepticism can be tolerated (like with JFK assassination). Which made me think that they were planning SOMETHING ELSE that would make 911 seem like old news.
