Since we reported the Kinect specs back in June, we've been trying to extract information from relevant sources as to what exactly the Wi-Fi Extension Cable included in box is all about. Info from this side of the pond has been as rare rocking horse manure. TekGolbin has managed to get an answer from Microsoft. Sort of an answer:
"The Wi-Fi extension cable included with the Kinect Sensor for Xbox 360 is for connecting to an external Wi-Fi adapter. This allows the use of a dual-band connection. The Kinect sensor and Xbox 360 S have their own built-in Wi-Fi, but the extension cable will be necessary for configuring a dual-band connection."
Clear? No. We're delving some more.
Source:
Tekgoblin