They said there is a few potential tweaks left to put into the dungeon, such as more skulls, things to make it look more dark, etc....
Also, PTR's always have new things put into them through the process, if you look at the PTR strings, there is mention of 5-8 features that are currently not in the patch notes even.
4
All i know is that Druid class will be playable after Necro launch but an assassin with shadow powers would be very cool .