I've been playing SoZ this week. I figured I wanted to see some of the assets in-game before using them myself to get some ideas.
So there hasn't been much direct progress on POE 1.5. I have finished all the questgiver conversations for the optional quests. Judging by the amount of time I spent on the rogue optional quests, all optional quests should be implemented this weekend if I don't spend too much more time on SoZ.