I got a note last night from Kai Aras about some demos he’s done using iOS to control the Philips Hue lights. He has an explanation on each video page about what exactly is going on, so you can read those as well.
In the first video he says: “Media is played by an iOS device which talks to the hue bridge in order to control the lights.”
In this video, “what you see is 3 living colors units lighting my living room while Airfoil is streaming music to an AppleTV.”