I am pretty sure turning off Wi-Fi doesn't really turn off Wi-Fi. It will still scan for Wi-Fi stations so it knows its location. But with Wi-Fi off, it will not try to connect to them.
I am not positive of this behavior, but I did turn off Wi-Fi and my iPod's battery still went dead albeit slower than if the WiFi had been on. So it was determined empirically.
It must be then, that "Wi-Fi off" means to Apple... "Don't connect when waking". Which is pretty darned cavalier usage of language, in my opinion. The iPod is only marginally useful because of its uncontrollable battery draining behavior.
