If the NHL ever wants to "hang" with the other professional sports, it's first priority has to be figuring out how to make the sport more affordable at the youth level. Outside of a frozen pond (no, I'm not going to include roller hockey) it's impossible to have a pick-up game. On the organized league level, the cost is out of reach for far too many to get their children involved in the sport.
My youngest plays basketball year-round. He's currently in two leagues which are really well-run. Each league has 15-26 teams, lasts about 3-4 months, keeps track of stats, gets jerseys, end of the season tournaments, middle school/high school courts...Combined, I paid $425 for BOTH leagues. Can that even buy a good pair of youth skates (that they'll probably grow out of after a season)?
I'm not sure how the NHL will ultimately solve that, but until they do, it will always be a niche sport.