I just stumbled upon a site from Philips where for 2007 games and DVD experience would be enhanced with fans, colored lights and speakers.
http://www.ambx.com/site/consumer/film
Never mind the fans and speakers, but it's the lights part which intrests me. It seems to work in the same way as their ambilight system. Using the video signal to drive RGB lightsources which can be placed in the room.
I've seen a DIY version to be used on a computer system with special drivers and fluorescent lights, but nothing for a normal TV/DVD (except for the real ambilight TVs)

It seems to be pretty cool to change the lighting of the entire room according to the scene on tv. Does anybody know if there are any systems available which are able to do this already?