During the updated Ask Me Anything segment on IGN for the Xbox One, Marc Whitten, Corporate VP of Xbox, said that the Xbox One will not require a plugged in Kinect to function.
In response to the possibility of a broken Kinect, Whitten said, "… the console will still function if Kinect isn’t plugged in, although you won’t be able to use any feature or experience that explicitly uses the sensor."
When Microsoft first revealed the Xbox One, the console would only function with the Kinect sensor plugged into the console. Obviously, you won't use the Xbox One motion gestures or voice commands without the Kinect, but it removes the requirement for those lacking space or those uncomfortable with the camera always pointed towards them.
As Microsoft continues to receive feedback, they continue to change or completely remove policies or features of the console. Just last week Microsoft changed their stance on the headset and will bundle one with every console.
The Xbox One will launch this November for $499.
Source: IGN