No, they're not. But not only because 3D screens and purchasable 3D media need to become mainstream first, but because not even normal 2D video is "mainstream". Allow me to elaborate:
If you're an amateur photographer with a camera, you have a multitude of free or low cost tools at your disposal (cameras/phones and software) that will make your photography suck appreciably less. Even if you're pretty serious about it and your photos are quite good, the average person that you show them to will swipe through your entire portfolio in a few seconds and move on. People take photography and photos for granted. Photographs nowadays are EVERYWHERE and people are just not going to invest time in looking at them. For good or bad, they just won't.
The same is starting to happen with videos. Everybody carries a video-shooting camera with them nowadays, but the videos that are being shot with it are the equivalent to un-edited snapshots and they just suck. If you're lucky, your video snapshot will be of some journalistic value and a news outlet will buy it off you. But other than that, it's just crap. Making a good video without good equipment and without good software (pirated software doesn't count!) is a pain in the ass. There is also no low-cost video-editing software that is up to the task of making your video not suck, IMHO (I'm open to suggestions!).
Adding to all this is the fact that videos just take time to watch. So, the proud owner of a video-capable DSLR or smartphone will pretty much be asking his/her friends to go through several minutes of shaky, badly-lit, unedited footage of some event that made them feel in a certain way, but took absolutely no pains to transfer that feeling to video. And now we get to watch this in 3D?! This must be a nightmare coming true! Look, home-videos are OK for what they are. They have had their place since the VHS days, but that's about it. Shooting them in 3D is not going to add to the experience. People will see your video in their Facebook news feed or whatever, click on it, watch the first 10 seconds and move on. Like photos, videos nowadays are also everywhere.
And the worse thing is that you can't really make them suck less. The cheap video-recording devices are there. We now need cheap video-editing software to go with it that will target the mainstream crowd (I would kill for video-editing version of Lightroom, for example). We need to create a "middle-class" of video-shooters that will have a creative interest in looking at 3D capabilities. Once we have this and once this has become mainstream, we can discuss about adding the 3D functionality into the stew. Before that time, 3D is just fluff.