One example: When doing usability testing it's pretty common that people get dizzy or can't use the glasses for 5 minutes+ (which in my book means...pretty unusable). Even fiddling with some of the recommended settings doesn't help all that much. So our next step there is to figure out a good prescreen ("carousel sickness" seems to correlate)
It's also interesting that after some preliminary/very quick research, VR is often either not compared to other options at all or compared to non-tech solutions (typically for training applications) whereas the comparison that I expected intuitively (Rift vs. 3D engine with just a controller) is rare.
It's fun fiddling around with this stuff and I'm looking forward to learning more about it in 2015 but my initial reaction is...sceptical. I may have access to a CAVE next year though :D