I'd drop Whitney for basically any of those guys.
Ranking them is tough, because these players bring value in different categories (Leddy very few hits but will get PP time; Carlson a ton of SOG; Staal huge hits low SOG; etc.) plus some have started very slow. My ranking for this year would probably be as follows, taking into account that it is relatively point-heavy (G, A, PPPs, etc.):
Faulk - big big minutes, incuding PP and SH, should translate into points even though he's only got 3 pts so far - I see him as the one who could explode out of this pack, given the opportunity, same as...
Carlson - Carlson would be at the very top of this list most years but he's in a bad state right now and it's showing in his stats, although he's firing pucks like crazy (29 SOG in 10 games). My feeling is he's a great buy low right now, as he could explode at some point, and if ever Green goes down...
Staal - huge hits totals and great plus minus, low SOG, but will get primo minutes (not PP) and has come out firing with 7 pts already.
Leddy - love his situation, should contribute points and good plus/minus, but very low hits and comparatively low ice time (Keith/Seabrook effect) caused me to drop him a little (originally had him 2nd)
Kulikov - slow start, but if that FLA PP ever gets humming, he'll produce
Gilbert - great stats right now, esp pts, but will it continue? With him you never know, and he'll never give you big hit totals.