Questions, Questions (Round Two)

Picking up where I left off the other day, this question comes from D.O. at Die By The Blade:

Scoring in the league as declined when compared with the previous two seasons, including a recent Saturday night that seen five shutouts.  Some people say that the trap is back in the game, others say the referees aren't calling the game as tightly as they were and still others say that defenses and goaltenders are just that good.  What is causing the decline in goal scoring and what should the league do to get goal scoring up?

Tell those darn goalies to stop getting in the way of the puck so often?

Seriously, my belief is it's a combination of games being called more loosely and a league-wide upgrade in defense.  As far as what the league should do, other than start calling the game by the book regardless of which teams are playing / which players are on the ice / which period it is and how much time is left in it / what point in the season or post-season it is, nothing.  Call interference as it's in the rulebook, and you'll see scoring increase naturally.