As yet we have had no real confirmation as to how the Ambilight system works. I know that James routed 1 or more GPIO lines to the micro USB to support the system but there have been no other details. In Gordon’s list of software improvements that he posted in the KS comments he did list a kernel level driver for WS2812B LEDs and from pictures of the Slice PCB those do look to be the LEDs round the edge of the board.
Does the Ambilight system also use WS2812Bs? A single GPIO line system possibly connected to the normally unused pin 4 of the micro USB port? Or is it something else? Which GPIO line(s) does it use? It looks like a really interesting system.