Well, if UBL uses a freighter enter the U.S. then D.C. will be spared because it is not a deep water port. Any number of other ports are possible, including NYC, Philly, SF, etc. Then again, you have to wonder what exactly he means by "the belly". He might have himself planted inside an 18 wheeler, along with a dirty bomb, and show up in D.C., Chicago or Dallas. I could also see him making one final video via mini cam. He might arrange to have Al Jazeera pick up a live feed 10 minutes before he detonates.