I mention it in every VR review I write, so I apologize if you've read this before, but it's important to point out that VR can make even a seasoned gamer weak in the knees if you play it for too long.
Sony recommends taking breaks every 15 minutes or so and stopping immediately if you start to feel dizzy. I'll add onto that by saying that you should slowly acclimate yourself to virtual reality rather than jump headfirst into it. Start by playing a game for a few minutes, ideally using the Move motion controllers while seated. As you start to feel more comfortable you can increase the amount of time you spend in the virtual world without coming up for air, and choose to stand to get the full immersive experience.
I'll also admit that the first time I tried VR, I felt very sick, and only after using virtual reality headset over multiple occasions could I finally overcome this feeling and start to actually enjoy VR.
My body, like yours, isn't used to feeling disconnected to the visual stimuli it's receiving. Even if you game for hours and hours per day, you still are sitting in the real world, periodically removing your gaze from the television to look at your cellphone or interact with another human being. In virtual reality, the only things you see are the screen and the objects on it, yet you can't physically interact with them. This leads to the feeling of disconnection and resulting nausea.
The other interesting symptom I had after extended use was a pretty awful headache. It might've been due to the lack of sleep I went through while writing this review (you're welcome by the way) or the fact that I put myself on a strict media diet of eight hours of VR a day for a week straight, but most nights I went to bed with puffed eyes and throbbing sensation right above my temple.
There are others who I've spoken to who have felt similarly without testing it for hours on end and with a better sleep regiment, and some friends who felt just fine playing longer on less sleep. This is a definite "your miles may vary" situation, but I just thought it was worth mentioning in case you get your own unit and feel similarly.
I'll end this section on a high-note: PlayStation VR is one of the better VR systems I've had the pleasure of using. Because it has motion controllers and offers enough playspace for you to stand up when you get tired of sitting, it's actually less likely to make you feel nauseated and achy than, say, Oculus Rift or Samsung Gear VR might.
PlayStation VR's future
Let me say flat-out: I can't predict the future, nor can I claim that I'm privy to Sony's plans for the headset going forward. But, one option I see for PlayStation VR is that it becomes a blockbuster accessory that becomes essential to the platform moving forward. There's a chance that it will sell so well that developers will feel that there's financial gains to be made creating content for the nascent medium and supporting it in its first few years of life.
But there's also another possible route for PlayStation VR – one in which the system gets a lot of hype and support in the first six months and then, skip ahead two years, finds itself on the same dusty shelf as the PlayStation Vita or Nintendo Wii.
From everything I've seen and heard so far, both at tradeshows and while talking to developers, there's a lot of excitement around virtual reality and PlayStation VR specifically. That lends itself to the idea that PSVR will be well-supported both by first-party developers and third party publishers actively trying to make the platform succeed. I only mention the latter because it's not a completely uncommon scenario – we shell out for technology that we think could take off, only to be disappointed when it can't reach critical mass and developers abandon it. (See: Microsoft's Kinect, 3D TVs and Betamax players.)
I guess what I'm trying to say is that there's probably a lot of potential here, Sony would hardly waste millions of dollars in R&D if there wasn't, and once we learn how to tap into it better by becoming native VR users, it's only going to get better. But, if you're scared to dive in head first, no one would shame you for waiting a few months to make sure developers are still on board before putting down your $400 cash.