The promo got me so excited. Looks like the show won't suffer from Sophomore Jinx.
LTIH - killing off Kate 2 seconds after one of my favorite couples ever got married will NEVER be forgiven, but God help me, I loved Miss Wainwright. I can't say I will miss this series. I hope its done because they didn't do Caroline justice after losing her wife. Just went downhill.
I think the time she takes between seasons is because she wants to give a good product and waits until she feels she is at a point to where she can write the next series. I do know for Happy Valley she was waiting for the boy to age because the final series will be a lot about him and seeing how teen Ryan deals with dear old psychotic dad.