In fact he is meaning USING nukes is his own right, a statement meant to prepare the world for his own wrath - a sort of nuke usage appology. THat could imply that he has nukes already and are making them ready.
Just as the war on drugs was a failure, the smugglers have used the same drug routes and readily bribe-able "reliable" custom officers to pass nukes. We certainly are seeing the tip of the iceberg in this story.
If the gung ho US forces go near Usama and are able to capture him, then that means he has no nukes. However, if he has nukes, he probably kept them for himself or kept some behind the lines as a mean of hostage taking of Americans. So the nearer we get to Bin Laden, the more likely US forces in Afghanistan will get nuked or some Western asset or country will get nuked.