Ok, this won't be a Killer App for PSVR, because it's still available on regular PS4. No VR needed to play the game.
You need VR to play the VR levels.
Speaking as a person who doesn't own VR, Dreams is the single title which could get me to buy one. The amount of content is just ever-growing, and you could get so many unique and amazing experiences in this that you couldn't have gotten anywhere else :P
Predicted 15+ million lifetime-sales for God of War: