The NHL should lower ticket prices at the very least as a courtesy to their fans who have still supported them. It would be good marketing for them because they would be retaining fans they already have with the potential to make new fans. Plus, many have been hit hard by the economy and do not have the additional income to spend on entertainment anymore.
The NHL should lower ticket prices after the lockout as a gesture, or rather peace offering to the fans who are willing to show their support by still attending NHL games after a lockout. The fact that fans are committed to supporting the NHL after a lockout earns them a small show of gratitude, lower ticket prices is the perfect show of appreciation for all the supportive hockey fans.
As a good faith gesture (and to get casual fans to budge), lowering prices would be a good idea for the remainder of this assuredly mess of a season. Let the fans know that you're sorry and say please come back, people will still be greatly annoyed that a lockout occurred yet again and will still hate Bettman but it's a good faith rebuilder.
Since the lockout lasted so long, it may be hard for the NHL to get people back in the seats. I know several friends who abandoned their season tickets due to the lockout. It may just be good economics for the NHL to lower ticket prices just to get fans back and watching games. They can always raise the prices later.