At this time every year we start to see some surprising scores in the NHL. Top teams losing to bottom teams that are out of it and playing for roster positions next season. This is what Ottawa has been doing the last several weeks to Philly and New Jersey. Ottawa could possibly be the reason the Devils miss the playoffs.
You also witness teams that are fighting for the 8th spot getting hot. Edmonton rode a late season push all way to Game 7 of the Stanley Cup Finals in 2006. Montreal and Philadelphia got in to the playoffs late last season and used the desperation they were playing with to upset Washington, Pittsburgh, New Jersey, and Boston to make the Conference Finals. Those top teams except for Boston didn't seem to be playing with the same confidence as they were during the season.
So for the top teams in each conference that are guaranteed to be in the playoffs they have overcome the issue that other top teams have faced - ramping up the intensity once the playoffs start. It is human nature to back off when the games aren't as meaningful.
The problem is that getting the #1 seed only benefits you 1 extra home game in the 1st round. And, if you lose Game 1 or 2 then the pressure is on. Philly, Vancouver, Detroit, Pittsburgh... must all find a way to consistently play an intense game, competing with desperation and being physical. The problem is that it's tough to just create desperation when the situation doesn't suggest it exists. Coach Laviolette of the Flyers was paraphrased by an announcer to say that "you can't make manufacture desperation". I would tend to agree with that statement. It's hard to convince yourself that a game is very important when maybe it won't change your position in the standings or the fact you will make the playoffs. Plus, what's the real advantage in having home ice anyway? It's not like the NBA. Last season was further evidence that you just have to make the dance and then see what happens.
I believe you don't try to manufacture desperation, instead you focus on pride in performance. Focus on execution - simple, smart plays like getting the puck on net and continuing those habits so when the desperation does kick in late in the season or the playoffs the intensity doesn't lead to inconsistent, erratic, or nervous performances. This of course is where the leaders in the locker room have to keep the standard of execution at a high level and constantly remind and stay on their team to focus.
So, the task in front of the top teams in each conference is to maintain or regain a high level of intensity going into the playoffs. Because they know that the teams that barely make the playoffs will probably have a lot of momentum and continue to play with desperation.