Would like to make a few points regarding VR:
1) This "Speculation suggests that were seeing the end of the early adoption for VR." is horse manure, even if the numbers prove that, which they don't, certainly not on the vive side as Stumpokapow pointed out.
Adding to that one just needs to look at the amount of countries that actually have the HTC vive or the oculus rift available at, to realize that well there is a significant issue there, I mean just on Europe alone the vive covers about half the countries there, now granted they are the biggest countries, it also doesn't have support for anything south of the USA, or Russia, or India and so on, but those countries that aren't covered also have people that would buy the headset.
2) They have failed significantly to showcase the hardware in stores, and for anyone that has tried something like the vive or has seen people try it, will know that this is a technology that leaves people very impressed, and from my experience non gamers are vastly more impressed by it than gamers, which does bode quite well for mainstream penetration of VR.
With Christmas coming around if HTC or oculus manage to actually put this in the hands of people so they can try it, it will increase the movement of units quite considerably.
3) Oculus touch will help a lot, there are plenty of Oculus users that probably haven't realized this yet, but motion controls are a game changing technology far more than the headset itself, it is once again also very good for mainstream penetration, since they are vastly more intuitive for non gamers than a mouse and keyboard or gamepad, within minutes I have had non gamers (people that really don't play games) be reasonably proficient at shooting, something which is really impossible with a mouse or a gamepad, where it takes days to months worth of playtime to get to.
This opens up more "hardcore" titles to non gamers, which once again will help increase mainstream penetration, since initial games will no doubt feature a lot more action oriented stuff, especially since that is when the immersion is stronger.
4) The amount of people with hardware that can run an oculus or an htc vive is a non issue, not for the amount of units a first gen version could ever realistically move, over 11% of the steam user base has a 970 or better, 1 year and half ago steam had 125 million active users, they have seen huge growth each year, so we can safely assume that that number is very significantly bigger now, but even at "just" 125 million that is around 14 million users with oculus/vive ready hardware.
200-300$ VR ready (better than the 970 for VR) have started to roll around relatively recently, so there is a very good chance that between that and second hand 900 cards we will see that number significantly increase, and once again this is assuming the steam user base hasn't increased, which it certainly has, at some point valve was seeing a 100% growth year after year, but even just a 20% growth would significantly change things.
5) Did anyone seriously expect the oculus rift and the htc vive to move millions of units with their first consumer version?
Because if so yeah that isn't really going to happen, it is both stupidly impressive (vive tracking is pure technological wizardry) but at the same time is also a "total piece of shit" that also happens to be crazy expensive, however it is for the most part relatively easily improved.
The resolution as mentioned is quite weak, but that is just a question of upping the screens, with shouldn't be too much of an issue as 4k screens on cellphones are becoming more and more prevalent, also as VR moves more units a better case presents itself for having screens made specifically for the VR headsets, instead of the ad hoc solution we currently have.
Cable management is a nuisance but not really an issue, but it is also already being worked on, although I don't expect true improvements here anytime soon, since it would require batteries which entails charging, and the batteries plus what ever wireless hardware would increase the price of the unit, which is non optimal at this point, and more importantly resolution is likely to get a significant bump soon, so what ever solution is invented would also have to work with what might be a couple of times increase in resolution.
Field of view is quite poor, this is already being worked on on the starVR which has 210º field of view, and it is just a question of time until it is adopted by future VR headsets, this brings some problems regarding resolution and so on, but once again resolution is also going to be improved.
Comfort, this is quite poor, but I hear PSVR is better, no idea haven't tried it, but it is also something that I suspect will improve significantly with each version as people make suggestions, try new things and so on.
Then there are some issues with each specific set, like htc vive strap system, or the lack of non destructive mounting options for the lightbase, or the rift lack of good support for people with glasses (I know you can use glasses, but I hear it is not great in comparison to the vive).
Basically it is really not what I would consider a true consumer version of the headset yet, it is an enthusiast edition so to speak, but if absolutely nothing else the potential for the tech justifies itself
6) Even if VR is a fad for gaming, it is not something that is going away it has significant potential for use outside of gaming, and the technology does work, so VR is here and it is staying, how much and how fast it improves is ofc something to be seen.
7) PSVR while it will almost certainly move more units than the first versions of htc vive or the oculus, does have what I consider a significant problem, which at least right now it is trying to go for traditional gaming with VR, and that is not at all where the potential of VR lies, once again HTC vive motion controllers and hopefully oculus touch are the true game changers of the VR technology, they are an entirely different way to interact with games, a far far more immersive one at that, which will truly allow for new experiences, something which I'm sure plenty of HTC vive users will agree, and can easily be seen by impressions on stuff like raw data and onward, which are more traditional games certainly, but done in a way that feels like nothing I have ever played, I am yet to see the person that doesn't instinctively try and dodge a shot in raw data as if they were in the game, regardless of how much traditional gaming experience they have.
To clarify that isn't to say I believe in room scale, room scale is a complicated beast
8) If you have simulation sickness of any kind on something like the htc vive, then you are playing a game that wasn't properly done for VR there is no ifs or buts, the htc vive when playing experiences truly made for it and made well will not cause simulation sickness of any kind ever, in room scale VR you move and you do in real life, and when space is insufficient you teleport which is not really something you see because there is a fading of the screen, so you can't possibly get sick.
There is ofc the question of what other movement systems can be implemented to avoid simulation sickness, which right now unfortunately is just the teleport, everything else can induce it depending on how sensitive you are, hopefully more solutions will present themselves with time, since stuff like cockpits while not an issue for most people are still an issue, have also personally tried doing a wheel chair kind of thing with instant acceleration and constant speed with a teleportation like fade, and it works really quite well for walking front to back, but it is not 100% without the strange simulation sickness feeling (even if it never manifests into actual discomfort or simulation sickness).
9) There is a very significant lack of good software for VR right now, that is ofc changing by the day, but it is absolutely a problem right now, as it tends to be with most new things, and to that point there is also a substantial amount of price gauging, with devs like crytek selling a 15 to 20 minute game for 50$, that doesn't help VR at all, PSVR unfortunately is unlikely to be any different with devs spinning crap VR adaptations and selling it, and without he consumer friendly refund policy of steam this is going to be a significant issue, that might poison the well a bit, I know that I for example don't accept anything less than 0 feeling of simulation sickness from my games, the you adapt while true is also totally unacceptable to me, and I suspect plenty of people that haven't bought into it yet.
Finally for my personal opinion on VR, I believe that room scale VR will not succeed all that well, I believe it will have a place in the future, and some games will support it, but think a "small room" aka standing experience will be the way VR will go all around, this is not because room scale VR isn't great, it is, but to actually benefit significantly from it, it requires more room than a significant amount of people are bound to be comfortable making or really have.
VR is definitely here to stay.
VR arcades will be able to provide experiences outside of what one can get at home, even a simple harness and some fans, and an extremely simplistic game can provide a wingsuit like experience which is something that most people will never experience, certainly not in safety (speaking of extreme wingsuit uses, not skydiving with a wingsuit).
VR isn't here to replace normal gaming, it is a new kind of experience, not really a new genre, but an entirely different way to interact with games far beyond the by comparison trivial difference between M&K and gamepad.
Oh yeah VR will probably be the first gaming thing to genuinely cause someone to die, either from tripping over trying to dodge something and hitting the head on something, or from an heart attack, because horror will be insanely good in VR, and if I had to bet the first true killer app, the kind of thing that makes people go crazy and talk about it non stop to friends and family will be an horror game.
Probably forgetting quite a few points to things people have brought up in this topic, but since no one is going to bother reading this, it is also not an issue.