Coverage from the 2015 ATC Warhammer American Team Championship has shown than Space Wolves are still in the top of the current game Meta.
As you might expect, Thunderwolves is the unit of choice, with 23 out of 29 Space Wolves players taking Thunderwolf Cavalry and Characters mounted on Thunderwolves.
On closer inspection, almost all of them were actually allied in for Thunderwolf Cavalry and only a handful of them were pure Space Wolves armies.
It just confirms the theory that the Space Wolves real strength is as an allied-imperial-multi-tool of sorts and a go-to powerhouse deathstar.
Anyway, take a look at the numbers and notes on the various armies below.
It's all very interesting.
40K Army Breakdowns
Space Marines: 36 (Of those, 6 are Gladius w/ Battle Company. Sky hammer is more prevalent
Eldar: 34 (Of those, 10 have 3+ Knights with 4 being most common)
Space Wolves: 29 (Of those 23 have Thunderwolf Deathstars of some type)
Necrons: 27 (17 are Decurions)
Imperial Knights: 25
Tyranids: 19 (All of them used multiple Flyrants)
Tau:19
Dark Angels: 16
Astra Militarum: 15
Blood Angels: 13
Chaos Daemons: 13
Grey Knights: 11
Officio Assinorum: 11
Orks: 11
Dark Eldar: 9
Chaos Space Marines: 6
Khorne Daemonkin: 6
Adeptus Soritas: 5
Inquisition: 5
Mechanicus War Convocation: 4
Skitarii: 4
Cult Mechanicus: 2
Harlequins: 2 (Both of them took only Harlequins)