Earlier quoted context omitted.
Content is precisely the problem. Carmack even admits as much here: http://uploadvr.com/john-carmack-talks-difficulty-mobile-pos... That guy's pretty outspoken. (And yes, he's referring to live action content; I presume mobile VR will be tilted more toward video streaming etc than gaming, but I could be wrong.)
I'm not a sports person, but your "live action content" made me wonder how awesome it would be to be a sports fan who could view 'the game' from the sideline, or an aerial cam, and to be able to turn and zoom a camera or to switch cameras – as desired! Better yet, to be able 'be the athlete'. Cameras aren't there yet , but imagine being able to watch the scenery as an Olympic down-hill skier as flying downhill - AWES…
The big problem that scares me is sports licensing and all the legal stuff attached.
VR will allow lots of cool stuff like that :) . One possibility I was thinking about was putting the cameras on the referees instead of the players themselves (for sports such as soccer).
But I think it'll happen as soon as there's a critical mass of people buying VR headsets.