The NHL has some of the best hockey players in the world. If fans want to see the best skills in the game, then they need to watch NHL games. The NHL franchises generate a lot of money for the businesses in the cities in which they are located. The league helps the economy.
Hockey is a perfect sport with imperfect people running it. The league makes a lot of bad decisions but what takes place on the ice is still wildly entertaining and save for a few needless expansion franchises a pretty competitive product with a lot of star power. Fans will turn out, as they should.
The NHL is not the only sports industry to have suffered a lock out. The other sports industries which faced lockouts, returned to fans that were excited (maybe a bit annoyed) but excited none the less. The NHL is no different. People have a lot invested in the sports, emotionally and financially, so one could pretty much surmise that true hockey fans will be waiting with open arms once the lockout has ended
The NHL is known for having die hard fans, I think even though this is the second lockout in an 10 year period, fans will still be loyal to the NHL. Although this was a long lockout that took over 6 months to resolve, I think most fans will be back in the arenas to watch their favorite teams play.