What does the NHL "need" ESPN for? To be on a network where it'll be the organization's 6th priority behind the Little League World Series and Poker?
No thanks.
I think the NHL is doing fine with the NBC deal. This postseason every single playoff game is going to be broadcasted on NBC's family of networks. ESPN would never dedicate that much airtime to hockey, nor would it commit to advertising the hell out of it the way NBC has.
I doubt hockey will ever pass the MLB or the NFL ... those two are firmly entrenched at the top of the American sports popularity chart. But the NHL is gaining substantial ground on the NBA, as
this story tells you.