This is a conveniently open-ended thread since there's not many recent topics I can dump some Virtual Reality thoughts in (except for In the News and Current Events, but that's more an archive for news than an area for discussion). I think that we're getting close to the beginning of a VR spring, with my guess for that being around 2021.
You could say that we've technically been at the beginning of the first real VR spring since 2014 or 2015 with the release of Google Cardboard and the Gear VR, but things don't really feel very spring-like with so much negative hype surrounding VR throughout the 2010s. Constant buzz about how VR is underperforming and not growing at the rate that some predicted, techno-skeptics saying that it's a failed industry, plenty of articles to go around where the focus is "Why hasn't VR taken off?" Feels less like a VR spring and more like a VR Mini-Dark Ages (with the true 'Dark Ages' for VR being the almost 20 year VR winter that lasted from the last earnest attempts at consumer VR during the mid-90s, up through Palmer breathing life back into the industry in 2012 with the Rift Kickstarter).
Granted, 2018 definitely isn't as dark as things were two or three years ago. The industry has grown, there's more positive stories mixed in with the doom and gloom 'the sky is falling' articles, quite a few people who wrote VR off in 2015/2016 are starting to get into it now, and those who've been paying attention for the past few years have much more solid footing for believing that VR has a good future than they would have a few years ago. Negative hype surrounding VR is still a very large part of the overall mood, but things definitely aren't as worrisome or scary as they were in 2015 or 2016, when there was much more of a witch hunt against VR for not being an immediate success right off the bat.
I think a lot of pieces are being set up in place for the next several years to be more transformative for the industry than the previous ones were. 2018 is the year where all-in-one headsets are becoming the norm, as opposed to 2017 which merely dipped its toes into those waters with a handful of such devices but was ultimately still more connected to the mobile VR era, which is a huge deal that solves a lot of problems regarding cost and convenience. 2020 is the first full year where 5G will be a thing, with VR livestreaming being a killer app. Virtual Reality lessons will hopefully become a very common thing assuming that teachers have even a modicum of common sense and understand how blatantly fucking obvious it is that VR lessons are more immersive, fun, and easy to understand than the "drone at the front of the classroom for an hour" style of teaching; Nearpod has been adopted by around 60 percent of school districts as of the beginning of the 2018-2019 school year in the United States, and though that wording isn't the most clear (60 percent of school districts doesn't necessarily amount to 60 percent of schools altogether, not to mention that even some of the teachers who do use Nearpod might simply use its other, non-VR services), I could see 60 percent of schools across the country using VR on a regular or semi-regular basis by the 2022-2023 school year, maybe. And, of course, there's the slow, day-by-day progress and growth that's ensured 2018 is significantly less negative than 2016 was, even without these game changers in place yet.
My guess is that 2019 and the earlier months of 2020 will be the last time period where the negative hype is strong (though it will gradually continue to grow weaker just as it has throughout the 2015-2018 period), where many journalists and random people predict that VR has been/will be a failure and that another Virtual Reality winter is destined to happen. 2021 is the first year I expect to really feel like spring; not in the sense of Virtual Reality being overwhelmingly popular necessarily, but in that it's found enough of a foothold that nobody is predicting the death of VR anymore. By this point I think it will be generally accepted common wisdom that VR will be a success and become an important and respected fixture of society, and that the nail-biting mood and gloomy stories of 2015-2019 will be a thing of the past (2020's tenor I think will be closer to neutral, neither the feeling of contentment and safety of 2021+ or the pessimism of the 2010s).
After that, I think VR will become properly mainstream around 2023 or 2024. You'll be able to take for granted that any random person you come across at the store or on the street at least knows about VR, and most people will use VR here or there even if they don't do so on a regular basis - for events like NFL games or presidential speeches, work meetings, or socializing with friends or relatives who live far away.