Killer App and VR is an oxymoron. The world has shown that its still lukewarm on the idea of strapping shit to their heads and pretending to be inside of video games. The software isn't realistic enough, it's too expensive... maybe in ten more years when things improve. But right now, nothing is going to "put it over the top". There's no SMB1 or Pong that is going to ignite it.
Well, there need to be more AAA games, and the price has to come down. It's still pretty power intensive.
But I've shown off VR to a lot of different people, men in their 60's to girls in their late teens. Everyone was blown away by the headset.
Biggest thing it needs is a reason for people to buy it, though.