Short answer, yes.
Long answer; USB ports are 5V per their specification. That's why you're finding a lot of devices using them as charging/power ports these days. With the old style round plugs, it was possible to put the wrong charger on the wrong device. Not possible with a USB port. The only caveat with USB ports is the current draw. The specification states 500ma or half an amp, but some devices can go slightly over and some ports do not support the full current specification. With wall chargers, it's rarely an issue, but can be with computer ports. The Tornado passthru (and USB charger) does approach the current limit. Unlikely to be a concern with a wall charger, but can be a concern with some computer ports, especially laptop computers.
Actually some USB ports can output at up to 10w. USB 2 defaults to 5w, but can output at 10 if the device requires it. A good example of this is the iPad. My iPad charges on my Mac Pro, but not my PC, as the Mac Pro checks the device first.