I'm not really sure what the Neo-Nazi's holding a demonstration at Gettysburgh has to do with a law abiding citizen with the proper concealed carry permits to legally carry a firearm in the parks. I didn't see anything in that article that linked the two issues together.
I have carried a firearm in the Smoky Mountains since the law was passed. However, because it is concealed, nobody would ever know I had it with me even if they were standing next to me fishing. Outside of hunting or back country camping, I'm not a big fan of open carry in crowded areas. I think it's asking for trouble or a reaction. Carrying a firearm for self defense is just that for self defense. It's not to go around saing "Hey look at me, I have a gun".
I've been to the Smoky Mtns. twice since the law was passed and so far, I've not seen anyone outside of rangers openly carrying a firearm. How many were like me with a concealed firearm is anyone's guess.
Jeff