EVERYTHING YOU NEVER WANTED TO KNOW ABOUT "DIRTY BOMBS" AND AL-QAEDA'S CAPABILITIES: An indispensable primer from Joe Katzman, regarding the ramifications of yesterday's arrest. Also, William Saletan has an excellent description of the consequences of the all-too-likely panic that would ensue.
In his chapter on nuclear power from the book A Moment On the Earth, Gregg Easterbrook refers to the debate over nuclear power as "trans-rational," where the logical factors concerning the subject are "not just ignored, but actively shunned." The risks of most radiation exposure are much less than people think, and the anti-nuclear power advocates (with their allies in the media) have encouraged such hysterical thinking over the last few decades. If a "dirty bomb" is detonated, we may see the consequences of enocuraging such untruthfulness.
(This is not a recommendation to build more nuclear power plants; they make very little financial sense because of the costs and time required to build - not to mention their current role as potential terrorist targets. As Easterbrook wrote: "Nuclear power was supposed to be dangerous, dirty and cheap. Instead, it is safe, clean, and expensive.")
(Note: All Easterbrook quotes are from memory - the book had a lot of good quotes that are easy to remember. If I have not rendered a quote with 100% accuracy, I will correct it when I get home and can retrieve my copy of the book.)
UPDATE: More on the same from Strategy Page.