Paris - in fact, all of France - has been under the highest security alert for the past year, and the President has extended the alert for an undetermined period of time.
If you're worried about coming to Paris in the near future, you might have a long wait on your hands.
There are armed soldiers patrolling virtually every neighborhood in Paris. Especially the touristy areas like the Champs-Elysees and the major monuments, the grand department stores, schools, churches, synagogues and VIP residences. There are soldiers in the Metro stations and even in the Metro wagons and on Buses. Your bag will go through Security checks at major monuments, museums and department stores.
It's a fact of life, not scary, most people are comforted by this security presence and go about their business.
The US government always issues warnings, often worded very sternly. Don't panic and don't try to read too much into it.
These are the main ideas to take away from these warnings:
1) Everyone should carry his or her own passport in a neck pouch. If something were to happen - or if you become separated - it's difficult to identify someone without a passport. The youngsters can carry a color copy and have adults hold the real copies in a secure pouch or moneybelt. The name and address of the hotel you're staying in should be included in each pouch, as well.
2) Protect your valuables. Put them away securely when not using them.
3) Avoid crowds of people who are obviously demonstrating. It's easy to cross the street or walk a little farther to avoid them. There aren't many of these events during the year.
4) Report any "suspicious object" to the nearest authority. Obey the police, don't argue.
5) Sit inside restaurants and cafes if it makes you feel more secure. But you'll miss all the fun of people-watching.
6) Keep abreast of the local news in English - http://www.france24.com/en/
7) Check in with your airline a couple of days before departure for any updates.