So much retardation so far in this thread.
You guys seem to think that the law is meant to encourage killing or "remove compassion". This is not at all the case. This law was passed for the same reason many states will charge you for firing warning shots-people were putting their neighbors and family in danger by firing errant shots to "scare away" the attacker. The efficacy of this tactic is hit or miss, at best. More importantly, however, its danger to innocent non-participants is known. So by making the choice binary, citizens are going to have to ensure that they are on-target and completely dialed in to the situation.
The issue is this: the only reason your gun should ever come out is because you absolutely need it. It shouldn't clear the holster unless you are positive that it is the only recourse you have left to protect yourself or another from certain death or severe bodily harm. So if you're in a position where you can just pull it out and don't actually need it as a last line of defense, then it should still be holstered anyway.
This also discourages complacency. A LOT of people seem to think that they are safe merely by owning or carrying a gun. They don't practice nearly enough, and they aren't proficient with the weapon on the move or in an open environment. They shoot 50 rounds into a static paper target at the shooting range once every six weeks and think they can defend themselves in a high-stress situation. This law will likely help ensure that people take their skills a bit more seriously, as they will no longer have the subconscious naivete of thinking they can merely present the weapon or fire off warning shots (into the floor hitting a neighbor downstairs, or into the wall where it travels into the next house while little Johnny does his homework).
[size=+2]THIS DOES NOT MEAN YOU CAN'T TAKE NON-LETHAL ACTION TO DEFEND YOURSELF.[/SIZE]
It means that if you're going to utilize a firearm, you should only do so as the last line of defense, assuming you couldn't reasonably run away from the area, use hand-to-hand techniques, or employ a taser/stun gun/pepper spray. Don't draw your weapon unless you need it and intend to use it. Simple.
Also, for the love of God, please don't promote any of that "hit 'em in the leg/arm" bullshit. I can't even be bothered to explain how dangerous and impossible that is.