It does not really send power to the camera. The USB input is a logic input with an impedance of a few ten's of kilohms (on the one camera I have seen a circuit diagram for !).
But something has to power the hub itself. When it says "unpowered hub" it actually means "no seperate external power supply - gets power from the computer its plugged into"http://www.ehow.com/facts_7536367_powered-hub-vs-non-powered.html
So if you plug a CA-1 into the hub along with a Canon P&S camera - where does the power for the hub come from ?
Not the camera for sure. Maybe from the CA-1. But in that case the hub will only have power if CA-1 pulse is active. If you are counting on the hub "turning on" and passing on the 5V USB signal to the camera, you better hope it happen fast enough not to disturb the CA-1 timing.
More of a concern, that camera was introduced in 2011 and it is not known if precision synch is possible.
Early in 2011 so we will have to see. Probably more concerning is trying to do precision sync from a CA-1. I'll have to look and see if we came up with a good way to do that in the new USB code. The issue is that you have to start the full-shoot on the rising edge of the full shoot pulse in order to be able to "sync" on the falling edge of the pulse. But you don't know its a full shoot pulse (rather than a cancel pulse) until you have actually timed to pulse width - too late to then also sync. This in not a problem with a conventional "one push" switch.