I think a good bit of the uptick in scoring is due to the continual raising of the NHL's skill floor. Just this season already you've seen guys like Paul Cotter and Brock McGinn pull off sizzling highlight reel skill plays for goals, just off the top of my head. Neither of them are known for scoring, but even they have an immense level of raw skill. It just puts into perspective how much better than that the bona fide superstars are.
I think offensive tactics in general are improving as well and making a goalie's job more difficult. Generally, if a goalie can see a shot coming and get into position, he's going to stop it. But teams do such a good job now of getting into the goalie's sight lines, deflecting pucks, creating rebounds, and generally pulling the goalie out of position that the job is becoming increasingly more difficult. Sometimes, even when the goalie plays perfectly, they can still end up with a goal against, either from a perfect shot, a deflection, or a pass across that catches them out of position.
Skaters are just too good right now for goalies to keep up, it will be interesting to see if and how the players and coaches will try to react to this new paradigm.
