Vancouver's top PK unit dominates the list, and their second PK unit is right near the top too. Of course, Vancouver also has good goaltending, and it's difficult to separate out which individual player is responsible.
[You might have also noticed that James limited his list to 140 minutes of PK time. That leaves off Martin St. Louis, with 133 minutes, and at -2, arguably the best PK stats in the NHL.]
I'm still not convinced that we can draw much of a conclusion from one year's worth of PK numbers, given how low the minutes are (