At last month's SID conference in Seattle, Microsoft's Applied Sciences Group demonstrated a 3D display technology that doesn't require glasses. It uses a "wedge lens" which modifies the critical angle of light coming from the lens/backlight to determine the direction and location of light coming through the LCD. The system also requires a camera to determine the location of viewers in order to provide a convincing 3D effect, but Microsoft's new Kinect (formerly Project Natal) should do the job.
There are some limitations to the system: A minimum 240Hz refresh rate is needed for two people to be able to simultaneously view 3D video, and the viewing angle is currently only 20 degrees, although Microsoft hopes to increase it to 40 degrees. Microsoft is also encouraging LCD manufacturers to go beyond 240Hz in order to increase the number of simultaneous viewers.
My belief is that 3D in the home won't really take off until glasses-free systems become practical, both technically and economically. We may still be five years away from that happening, but once it does, demand for 3D will explode.