There are those who may remember when the NHL actually had competition in the form of the WHA. There are a lot of knowledgeable hockey people out there who remember way more about this league than I do. The only reason I have a smidgen of a recollection at all is because the Winnipeg Jets originated there and won the Avco Cup three times in 1976, 1977, & 1979 (i was 6, 7 & 9 yrs old).
The WHA was also the league where Wayne Gretzky cut his teeth as a professional hockey player.
The league became relevant and a threat to the NHL when it managed to successfully challenge the reserve clause which bound players to their NHL teams even without a valid contract, and allowed players in both leagues greater freedom of movement. The Jets did what was unthinkable during that period and signed Bobby Hull to a 10 year $2.75 million contract. An absolutely absurd and unheard of professional hockey contract at the time and it earned Hull the nickname of "The Golden Jet."
No doubt you see where I am going with this. The NHLPA's only real leg to stand on is to create an environment where the NHL isn't the only alternative. Sure the KHL exists, but most players from North America and many from Europe don't really consider it a permanent career choice....yet. The KHL could conceivable create a rival NA league that could upset the balance of power, particularly if it teamed up with the NHLPA and every other potential owner who has been snubbed by Bettman and the league (Hello Jim Balsille).
Granted, the KHL is still in its infancy and something of this scale is impossible to get off the ground quickly and would be scoffed at by many including the NHL. However, if the Bettman and league continue to be reckless with their demands they will eventually find themselves fighting to retain the best players in the world.
Thoughts from the Left Coast