StudioTan
Hold on, friend! I'd love to share with you some swell news about the Windows 8 Metro UI! Wait, where are you going?
Why doesn't "xbox on" work on my console?
I find that it helps to say it clearly and with a slight pause between Xbox and On. It's still less reliable than other voice commands but it works the majority of the time doing it that way.
Also, obviously make sure you set the Xbox to go to standby mode instead of shutting down.