Responding to questions in a Reddit thread about the Xbox One’s power states, Xbox director of product planning Albert Penello stated that the system would rouse from standby faster than a TV turning on.
“[Standby] is the mode we’d like to see people in, obviously, so you get back to gaming or watching TV really quick,” Penello wrote. “From standby, it’s likely the Xbox will be on before the TV is completely powered up.”
Of course, this calls to question how long the Xbox One takes to turn on from a completely powered down state. Then again, most systems wake up faster from sleep than a total off state. And TVs, in this arrangement, are presumably completely off.
Suppose we’ll find out soon enough when the Xbox One launches November 22 in North America and Europe.