I've been quite impressed by the Pittsburgh Penguins this playoff season. Their goalscoring expoits are attracting all the headlines, but they are also playing a strong all-around game that is completely overwhelming Carolina at the moment. I think the Penguins will put up a much better fight in the Stanley Cup Final this year, assuming they finish off the Eastern Conference Final series that they currently lead 3-0.
Even though the Pens made it to the Finals last year with many of the same players, their underlying numbers are quite different. Last year's version was not as strong defensively, and depended on goaltending to keep the puck out of their net. The '08 squad was outshot 610-594 in the playoffs, and Marc-Andre Fleury's .933 save percentage was critical for their goal prevention.
This year Fleury has just a .902 save percentage in the postseason, despite facing easier than average shots against and playing on a disciplined team that has not taken many penalties. By my shot quality estimates, Fleury has cost his team about 9 goals compared to average, which is more than any other goalie in the playoffs (although that is partly because most of the other goalies who played poorly went out in the first round). This matches my subjective view that he hasn't been particularly good.
Despite this the Penguins are winning, often in dominating fashion. They have become an outshooting team with a significant 569-460 edge in shots, which has allowed them to average an outstanding 3.7 goals per game despite posting what is for them a typical shooting percentage. Through 2+ rounds this year they have already scored as many goals as they did through 4 rounds one year ago. The Penguins are not relying on percentages but are simply outplaying their opponents, which is the mark of a strong team.
Fleury's play hasn't been a concern as of yet, although it might be soon in what is expected to be a closer, more tight-checking Final. Pittsburgh likely won't be able to count on an outshooting advantage against their Western Conference opponent, which means that the play of their goaltender will become more significant. Fleury is certainly capable of doing better, however, and if he can pick up his game and Pittsburgh is able to add solid goaltending to the offensive fireworks of Crosby and Malkin then they are a strong contender to win it all, even if they have to once again go through Detroit.