My predictions:

Lestrade will ask either Sherlock or John's advice on asking Molly out. ( I do think he's interested but also gunshy).
Sebastian Moran will target Molly, and Molly may kill Moran, and have huge character development.
Mary will save Sherlock back and maybe die in the process, creating weirdness with John. I can't figure out what they'll do with the baby.