The tier set bonuses have been announced and the feral ones are as follows:
Item - Druid T15 Feral 2P Bonus (New) Predatory Swiftness grants you an additional combo point on your current combo target when consumed.
Item - Druid T15 Feral 4P Bonus (New) After using Tiger's Fury, you gain 40% increased critical strike chance on the next 3 uses of Mangle, Shred, or Ferocious Bite.
It seems the 2P forces you to spec DoC as using PS without DoC but with HotW/NV is useless.
The four piece is rather interesting; critical strike is becoming less useful as we get free 40% crit every 30 seconds for our main CP generator and execution ability and with Blood in the Water, FB will crit nearly all the time. Same goes for Shred, which deals increased damage versus bleeding monsters, hence becoming better than Mangle.
What are your thoughts? Need tweaks?