From PTS notes:
Item Sets will now drop for every item slot.
This excludes the Agility, Endurance, and Willpower jewelry sets.
Sets that grant a bonus to melee damage will now drop more intelligently (i.e. a set with melee damage will no longer drop with a bow or stave).
So with dropped sets dropping in all places, looks to be including jewelry, it seems to open up quite a bit of customization options.
(Just wish I could get 3piece Julianos rings)
Does this have a possibility to change what's considered BiS?