http://en.wikipedia.org/wiki/DLP "Light source The main light source used on DLP-based rear screen projection TVs is based on a replaceable mercury vapor arc lamp unit (containing a quartz arc tube, reflector, electrical connections, and sometimes a quartz/glass shield), while in some newer DLP projectors high-power LEDs are used as a source of illumination."
From looking at other sites the DLP HD4 is being used in devices at the moment. Unless TI have developed their own laser light engine they will have to go with something else.