traveling "light" is a very subjective term. on a recent trip back to Taiwan, I decided to travel light; I only brought the 5D Mark II with a 16-35mm f/2.8 L II, 24-70mm f/2.8 L, and 100mm f/2.8 L Macro. I debated whether or not I'd need more telephoto capability, but the more I travel, the more I realize that I will only ever need telephoto lenses when I explicitly set out to shoot material requiring a telephoto lens -- sports or animals. Paris doesn't seem like it'd require either. That being said, the 100mm Macro was fairly light and I didn't mind that I brought it in case.
beyond that, I had to haul my wife's t2i and sigma ultra-zoom lens. when I weighed my backpack at the airport, all told it was 15 or 16 pounds. with chargers, batteries, extra memory, cleaning kit ... you get the idea. (edit: for clarification, to me this is light. I didn't have to bring my 70-200 or a tripod) since you're only carrying the one camera, I'd say bring the 17-40, 24-105, and 70-300! you can always leave a lens or two packed in the hotel room if you decide you definitely won't use it that day, but that way you won't regret not having brought the right tools. you should end up with a 10 lb or lighter pack if you do things this way, and even lighter when you are holding the camera and lens in your hands.
have a great trip!