First off, yes there is/are information that the government should not share with the public. If true, this could be one of them. However, the Nuclear fatwa has been out for many months now, it is not anything new.
As far as a true nuclear threat, combining the fact that OBL has one supporting his desires and two - the prime opportunity the election period provided, no nukes went off. OBL's nuclear capabilities, though some here would rigorously disagree with me, are probably not there yet. The most likely sources would be Pakistan, which likely kept close hold on its nukes to counter India's threat, and Iran which is still developing. There have been ample opportunities for use. It is not a precision weapon, such as flying into a building or needs to be close enough to inflict damage such as a car/truck bomb. In my judgement, he doesn't have them yet, but desperately wants them.
For the sake of argument, 'Z, let's say I gave a creative guy like you $2 Billion dollars in cash and heroine, and bet you another $2B that you couldn't buy a number of nukes (let's say... TWENTY). In order to collect the bet, all you have to do is position them in 20 major cities around the world within six years.
What do you think? If you couldn't do it, I'm *certain* that I could, and UBL is significantly more motivated that you or I in this regard.
Sleep well
sub6