I don't think that Zucker or Coyle are suited to the PP. Zucker has all sorts of goal scoring skills, but he is best when he can make use of the whole ice surface, as opposed to the small area, puck control type PP environment. Coyle...well, he's good at getting and maintaining the puck along the wall, and should be able to be a net front presence, but i just don't see that making up for his lack of shooting and passing.
Granlund runs the PP from the wall, and is very good at it. He is also elite at zone entries, which is an underappreciated skill.
Koivu only seems to be out there to win draws. Otherwise, he's a slight improvement on Coyle.
Nino has to be a fixture on at least one of the PP's. To me, he and Parise have similar strengths. Excellent around the net, good in small spaces, scorers, decent forecheckers who can possess, or re-possess the puck.
Staal seems to make things happen, but I can't point to any one skill that he has on the PP, besides the ability to shoot to score, size/reach, and being able to make the right play at the right time. He's OK on FO's, I guess? On second thought, he's an underrated sniper...just doesn't look like a prototypical one, i.e. Tarasenko/Ovi/Stamkos/ Shutt/Bossy/Vaive.
Suter is controversial... great on zone entries, and overall a steadying influence when setting up in the zone. His lack of urgency can be frustrating.
Dumba seems made for the PP. Spurgeon is pretty damn good, too.
I am hoping that in the future at least one of Sokolov , Greenway, and Kunin end up being on the PP. I can see Greenway being really disruptive down low, and both Kunin and Sokolov have proven to be shooters/snipers in the past. With Dumba/spurgeon on the point and a sniper down low or along the wall, we'd be in pretty good shape, especially with Granlund's newfound willing ness to shoot.