So I've seen one tutorial (Brackey's one) and Unity LA keynote about new version of 2D character rigging, but can't find a way to download this package myself. Is there a way?
It might be a package in the Unity 2018.3 beta that you can download? They're planning on officially releasing the 2D Animation Package with Unity 2018.3 sometime in December so you wouldn't have to wait long anyway. The Unity 2D team is planning on talking more about Phase 2 in a couple of weeks. I tested Unity 2018.2 and I can only download Phase 1.