There is about as much a chance of Al-Quaeda getting nuclear weapons from any, that is ANY country that has them, as there is of Pat Robertson and Sarah Palin and the gang getting a hold of U.S. nuclear weapons.
In Pakistan, for example, (if Pakistan is one Muslim country you're thinking of), there's no chance. According to an expert on Pakistan and south Asian politics, scholar and activist, Tariq Ali (you can Google him), there's no chance.
Tariq Ali points out that the Pakistan army is a half a million strong. The nuclear facilities in Pakistan, he says, are the most heavily guarded installation in the country, and the fear that Islamic extremists might get their hands on them is just not a credible concern. It makes sense. I'm sure the nuclear facilities here in the U.S. are the most heavily guarded facility; I can't imagine the same not being true for India, China, Russia, England, Israel (are they admitting they have them yet or no?).
And of course, even if one could (as inconceivable as this is) procure one -- its not ready to fire; this has to do with a complex of firing 'codes' and so forth; I don't know the details but there are many, many, many details.
And consider this. Don't forget George W. Bush wrecked an entire country, Afghanistan. Why? Because the Taliban wouldn't hand over one man: Osama bin Laden. I think Al Quaeda realizes that if they (and I understand they're only at two or three thousand strong) ever got one and the United States ever found out and thought they might be thinking about considering using it, whole countries in the developing world would be made to pay the price. Nixon called this the 'mad man theory' of international diplomacy.