Fear mongering at its worst. If you believe this nonsence go live in a fallout shelter. There are NO suitcase bombs! Its a myth. If old Osama had em--he would have used them up by now. He doesn't have time to sit on them. Now, that doesn't say he's not planning on a big attack--But it will be something like the last one--use our own stuff against us. Take over a nuclear plant and let it melt down, Take over a chemical plant and blow toxic gas into the air, or crash a Gas truck into a high rise or Vegas casino. They will use what's at hand and not bring in Nukes. That will take planning. They may even go back to airplanes as weapons. Who's to say they don't rent a lear jet (they got money)--load it with "Photographic equiptment" (explosives) and have a pilot crash it into something symbolic? There are so many ways to attack us that do not need Nukes.
See my 18 above.
Am not living in a fall out shelter but based on the events of 9/11 would not rule out a nuclear or some other chemical/biological attack.