First of all, hunters are already in a shotgun only zone. I don't even think you are allowed to use a rifle to hunt in Maryland. I don't think too many people will be too keen on walking around suburban Maryland with long guns for quite some time. If they do, they have a need to see Darwin.
I am sure the sniper feels a whole lot safer now! How's this for a catch 22....You have a pistol in your posession, you see the sniper and dispatch him without hesitation, only to face a 20 year conviction for violating the governors order and carrying a concealed weapon without a permit. It would happen you know.
What about banning bows and arrows? Is the governor feeling ok? He might need some quiet time.