Well this is more on gun control in general, but I find the idea of millions of red necks packing heat to be pretty damn scary.
I know some people think it will be used for self-defense(never mind it empowers the offense as well) but the idea seems laughable.
3 AM, some armed, professional criminals enter a house. Bob, our middle aged, rather obese, suburbanite hero decides to take a stand. He somehow has enough time to unlock his safe, load his gun and undue the safety by the time the criminals reach his bedroom. Bob then manages to take out all four armed men by himself, without any of his family of himself getting seriously hurt; way to go superdad.
Now if you ask me, there's something wrong with scenerio. Something I like to call "probability" which speaks against the average civilian effectively fighting off armed robbers.
It seems to me the civilian will only manage to get himself shot under such conditions. Now there is the chance the criminal(s) will not come with guns of his or her own, but
a) you are probably not going to know this when the confrontation starts.
b) is the small chance of this really reason enough to allow all criminals and psychopaths easy access to weaponry.
Lets not forget most murders are what are called "crimes of passion" as well, meaning they are committed by people during extremely emotional times. This would probably be avoided if they didn't have such an easy way to kill people i.e. guns. Now I imagine they can use knives, but you can counter that rather easily with, lets say, a baseball bat or by running away.
I've also heard it mentioned that we need guns in case the government decides to opress us.

Please. Imagine this scenerio. a professional army with tanks,choppers,assault rifles,trained/professional soldiers vs what? a mob of civilians, scared ◊◊◊◊◊◊◊◊, armed with hunting rifles.
"Yee haw, just shoot em there tanks in their weak spots!"
It'd be a slaughter. The days of civilian revolutions are over.
If the government really decided on such an action we can only hope for one of three things 1) Reform. 2) Rebelion within the army or government. 3) Foreign invasion.
Armed civilians would make little to no difference, and would probably end up getting themselves as well as others killed. You certainly wouldn't see me going out to meet Navy Seals, Delta Force and Rangers on the battlefield, even if you gave me a chain gun, let alone a shotgun.
Seriously, I think these pro-gun advocates watch too many action movies.
In real life if civilians try to stand up to professional armies or armed criminals, they get butchered. Maybe use up some of the enemies ammo. That's about the extent of their effectiveness.
This is more true with the more professional and high-tech the given army is, and the US army is pretty damn professional and high-tech.