I think that probably feel lefted out like the last season and that molly will probably regrate her dission on that guy she was with and be with Sherlock that's what I think anyway it could be wrong so don't hold it agaist me if my hypothesis is wrong o be like oh my if it's true so don't be mad.
I think that we will be introduced to the third brother (hopefully Moriarty), and I hope that Moriarty's fake death method will be a lot più exciting and interesting than Sherlock's.