Well, I suppose technically you could say "Xbox On" to your Xbox One right now. Nothing will happen, but you could try. But after the next update Australians will finally be able to say "Xbox On" and have their Xbox One actually turn on.
It's one of those small things that seems insignificant, but you just want it for some reason. You want to live the the future and you want to be able to do cool things.
Xbox On functionality will appear after the next update.
Australians who have been lucky enough to get access to the preview of the update actually already have the "Xbox On" functionality, so if you're one of those lucky few, give it a bash. I'd try it, but Kinect doesn't understand a single goddamn word I say anyway. It is the one drawback of being Scottish.
In addition the voice functionality, this update will also herald the new Media player and enable MKV playback on the Xbox One. I've been waiting a long time for this one. Surprised that the Xbox One is first off the boat. Pleasantly surprised.