Yeah, success in the NHL is often measured by cups, but their is a lot of luck and variance that goes into it. In Reality, a team is either well built to for long term success or it isn't. The early post lockout Canucks were a great team for a lot of years, that did everything but win, but are viewed by many as a failure. LA was built to be good, but their window wasn't large, but they managed to have the right breaks in the right years and win two, were they really that much better than the Canucks?
Washington was good for a decade, kept losing in game 7's to the only team that was statistically likely to win more cups than them, finally broke though, but has just one cup, but it's hard to argue they weren't better built overall than a team like LA, and as a whole that Cup lets you appreciate the other things that team accomplished (multiple presidents trophies is now a feather in the cap, not a further sore point).
Tampa has been a good team and well managed for awhile, they will take a hit, like all great teams, but they will still fill their roster with good players on good contracts, and be amoung the teams that can compete even if they don't win it this year, and the real question is going to be, if they don't win it this year, and they start making management mistakes going forward, will current management have squandered what Yzerman built.
The best way to make a team a championship team in the NHL is not by loading up for a run, simply because adding one player doesn't up your odds from 20% to 45% like it can in the NBA, it's about making choices.
Would you rather load up and be the favourite with 20% odds but then have a tear down coming? or be a good team for 8-9 years with 12-15% odds every year in that stretch. Longevity is more likely to get a cup in the current NHL, than big swings, and Tampa has managed to become a favourite with an eye to the long term, and should be commended even if they don't get there.