Sure, there's always a chance. But compared to the rest of the region, Jordan has seemingly figured out a way to keep things quiet. I'd actually like to be there in a time of moderate unrest (though certainly not if it was on the scale of what is happening in Syria). My first choice was the West Bank ETA, but that got shut down last summer before the applications were even due. My biggest concern is what considerable unrest would do to the Fulbright program, as it doesn't seem like it continues to operate in unstable countries.