For whatever reason, the games industry has decided that these things are amazin' and everyone has to do it. Of course nobody is doing it, I mean Occulus has a prototype out that has some pretty major issues and no release date for final hardware but that's it. Everyone else doesn't even have any hardware at all.
So of course what companies lack in deliverables they make up in hype. Talk about how damn cool their shit will be, how the world will be changed, etc, etc. Particularly since it doesn't seem any of them have a solution to any of the issues. Most of the things aren't solved by magic, but by better technology which is being developed by other companies. Things like latency/refresh are largely going to be a combination of higher speed displays and faster GPUs to drive them. Well, those will get developed I'm sure, but by Samsung or LG, not by Occulus or Valve.
Valve has also been having some problems in this area as of late. They seem to wish to become more than just "the guys who run Steam" which makes sense, because Steam is super profitable but also unstable, people could migrate to a different store en masse for various reasons. However their "no bosses" organization means that a lot of playing happens and not as much delivering. So you see hype and noise, but not necessarily final products.
The Steam box is a good example. Heard lots about that for a long time, some hype videos about their controller, and yet nothing is on the market, and there is no date when anything might happen.