They havent sold as well as the Manufacturers had hoped for and it hasnt really caught on. It doesnt help that there is little in the way of 3D content either Televised or discs to buy still and that the manufacturers couldnt agree (again) on the glasses aspects and i believe there are three different versions available. There is also a possible Health implication of what damage it may do if users watch for prolonged periods of time. This may be more relevant to gamers when 3D games really start to take off, although the last i read this hasnt been proved it seems to be just some medical experts opinions and others seem to think it is fine. who knows, bit like mobile phones damaging your brain scenario?!
All i know is that it doesnt interest me at all, well maybe when 3D porn comes out i'll have a gander!!