I just read the notes. Basically, here is the summary:
- Seasonal buff announced based on kill streaks: a stacking bonus of 0.05% movement and 0.1% damage per stack up to 1000 kills, additional effects occur at certain kill numbers, the stacks disappear after 5 seconds of not killing or hitting anything (similar to Gogok), stacks are shared in a group setting.
- Crusaders and Monks got their new sets with a few adjusted supporting legendaries (Fist of Heavens-oriented for Crusader and Tempest Rush/Sweeping Wind-oriented for Monk)
- Barbs got a number of adjustments on various legendaries and sets for Rend, Seismic Slam, Hammer of the Ancients, and Call of the Ancients
- Wizards got their Chantodos pruned (goodbye Vyr’todo GR dominance)
- Necromancers got their Bone Ringers capped at 60 (goodbye thorns Necro RGK)
- Witch Doctors and Demon Hunters got NOTHING LOL
- Squirt’s Necklace bug (buff loss due to ground effect) fixed
- Misc minor QoL stuff: auto-pickup GR keys, LoD gem is now a higher priority gem drop from GR boss
From the DH perspective, we now can probably participate more often as RGK but since Starpact was not nerfed, Wiz still are WAAAY far ahead for trash clearing.
TL;DR:
Barbs 
@ refurbished toys
Crusaders 
@ new toys
Demon Hunters 
(do we still exist?)
Monks @ new toys
Necromancers 
@ Bone Ringer nerf, 
@ no other nerfs
Wizards @ Vyr’todo nerf, @ no other nerfs
Witch Doctors (do we still exist!?)