Having just fully researched and purchased a 3D television this month, I have a lot to say about the subject. First, Glasses free 3D tech will not take off. The technology we have available for this uses prisms and requires the user to sit literally in the sweet spot for it to work. Go to your local BBY and take a look at a nintendo 3DS on display to get an idea. Too far away, no 3D, too much to the left/right no 3D. It's a limitation of the technology. People simply won't tolerate that.
When I went to purchase my TV, I thought LG's passive 3D was going to be it. Then I got a look at it literally side by side with a samsung active 3D set. The way passive 3D works, the vertical picture resolution is halved. Each alternating line goes to a specific eye. It's like taking a 15 year step back to interlaced frames. Instead of 1080p, you start with 1080i, and each eye is only getting 540 lines of that. The 3D effect it creates is quite good, but you can easily see jagged edges and can see the lines during scenes with a lot of movement. The picture is also noticeably darker, also due to interlacing. The glasses are the same things you use at a theater, but the technology in the theater is different because they use two full resolution overlapping frames from a projector rather than half height interlaced frames. The same thing can't be done with current LCD TV sets. This is why there is such a quality drop. I'm not sure it's even possible to duplicate 3D theater tech on the small screen. You'd actually need to use a 3D projector with independent polarization to get this.
The samsung set uses active 3D. The glasses in the display are of lower build quality than what is included with the TV itself. The included glasses are not bad at all. They are actually much more comfortable/lighter than theater glasses, and they even fit great over my wife's corrective glasses. They are very sleek and wrap around your face. The glasses are sort of molded in a circle and are very flexy. The electronics (which are already tiny) are in the ear pieces rather than the top, so there is much less weight on your nose.
The 3D effect created here is also good, but not quite like a theater. Instead of stuff popping off the screen, it just goes really deep. It's like looking at an aquarium through the glass. The surface of the TV is where the 3D effect begins, rather than where the viewer is sitting. The picture however, is perfect. There are some criticisms about flickering and/or eye strain. In my experience with it for the last 3 weeks, I have watched up to 5 hours of 3D content at a time. I did not notice any flickering with the TV, but if I looked at something like the time on the cable box, I could see it subtly blinking. My eyes were tired when I was done, but no more so than looking at a computer screen for just as long.
My TV also has 2D to 3D on the fly. It's not super impressive, but it does work. I watched Fast Five and used the 2D - 3D conversion. At no point did the 3D look wrong, but there were some instances where the 3D was less pronounced than others. It was kind of like watching tron legacy in the theater with the mixed 2D/3D. There are a couple scenes where the camera is circling the large statue in the middle of city. On my TV that scene looks like it was shot in 3D. The whole hill side of the city and the statue clearly have depth.
To say that it's a failure of the technology, that it would hold back consumers from buying into 3D or that it's inadequate is a complete mischaracterization of it. It's a value add, something you can use if you want. It's not the full capability of the tech.
I think the issue is more people that just bought 2D sets within the last couple years talking crap about the tech because they don't want to drop the money for new set, and need to feel better about their purchase. That or a lot of commentators have ridiculous expectations. The Holodeck? Come on.... I've seen a 3D holo of Christopher Walken at universal studios. It to date is still the most awesome display of tech I've ever seen, and I've never seen it anywhere else. To say that TVs have to do that to make 3D worth it is absurd. It wouldn't even be a "TV" any more.
I'm still very happy with my set & it's 3D, I wouldn't trade it for any other TV out.