Josh Mosqueira just announced Season And a Ladder-Like System are coming in the first Major Content patch during the RoS Release Event!
This system will come out during the first major Content Patch (not first patch)
The devs are thinking about adding Seasons-only legendary items!
Wyatt Cheng announced "Tiered Rifts" where players are going to compete with each other in Adventure mode and be a part of Leaderboards.
Though they may not go back and add new affixes to old Legendaries that have none. The new ones they add with patches will have fun effects.
Jó hírek

