Thanks to everyone for your responses. They have echoed my own belief that while recent event are terrible and will probably continue I will not change the way I live or travel.
I will be more aware of surroundings and events, stay away from large groups and since we will be renting a car and driving we will not need to use mass transit.
I'm assuming that security at CDG will be more intense and with only a 75min layover between my ATL to CDG and CDG to Nice I think I will call Delta and see if I can get later flight to Nice.

Thanks Again All