What a great topic! Maybe take live shots from clubs across the country in a big montage.
Or follow the stages that a salsero/a goes through from novice to totally addicted. It could be very funny, the late nights, bloodshot eyes, sneaking out to salsa, no sleep, practicing your steps and turns while you're brushing your teeth.
Or a dance off in the middle of the street. Two couples dressed casually but hip in jeans. May sound cheesy, but I think if done right, could be very cool.
Another funny idea would have people dancing in everyday places, at work in the office. In line at the movies, the aisle of a grocery store. The waiting room of the doctor's office.