I think a lot of them think that it will be "militias in the woods against the national guard, winning through guts and woodsmanship" or something, conjuring up images of units v units battles from two centuries ago, rather than the pattern seen all over the world for the past couple of decades - urban guerilla strikes.
The people won't fight the army, because it's not the army that's directing their lives. The police are the most visible authority of the government to the domestic population, so if the 2nd amendment is to be used in it's original intent, it will look like Dallas as you say, and not some paintball woodlands adventure on steroids. Two centuries ago, the government sent units in ships over the sea from a foreign land. In the modern era, the government is composed of the same citizens that dream of fighting it.
Nothing will change, though. Unless a rash of copycat crimes happens, there'll just be the same speeches by the same talking heads, and it won't make a lick of difference.
