I think some of you may misunderstand this law. I don't believe that Yahoo isn't wording it properly; you are not authorized to shoot someone because 'you think they might be scary.' In this case, "perceive as a threat" is toning it down considerably. Under the current law, you could be taken to court if you shot someone who pulled a knife on you. Under this law, you're legally allowed to
defend yourself and your family without running away first. Makes sense to me.
This law isn't changing the proper application of deadly force; it's saying that you don't need to attempt to run from someone who's threatening you. Under the old law, unless you were at home (or in your car, IIRC), you'd have to try and evade your assailant before the use of deadly force was permitted. Under the new law, if someone pulls a knife on me, I can shoot him. I don't have to run. That's the way it should be.
Again..this isn't expanding the situations in which deadly force may be used..it's expanding the area. If anything, it will reduce crime.
+1 for Florida..not quite as good as Arizona yet (open carry without a permit is legal), but it's getting there.