Some theories I have for this episode and the rest of the season:
Littlefinger is behind the Sons of the Harpy
Tommen and Cersei will be dead by the end of the season (peasant revolt for Tommen, Jaime kills Cersei before she can burn everyone in KL just like the Mad King)
Little finger will be the main impetus in the revenge killing of Walder Frey (we'll see him motivated by something other than his own personal gain... revenge for Catelyn)
Davos will learn about Shireen's death just in time to die heroically, saving someone else during or just prior to Bastardbowl
Brienne and Podrick reunite with Jaime and Bronn
Loras converts to avoid prosecution from the high Sparrow, and no one cares
Jaime has to bring the Lannister army to KL to try to remove the Tyrells and quash the revolt
After Tommen and Cersei are gone, Margaery is made Queen by the Tyrell army
The WW army crosses the wall and destroys the Night's Watch
Tyrion convinces Dany that diplomacy will work and bring Slaver's Bay under control, especially under threat of the Dothraki horde
Dany begins plans to conquer Westeros after hearing of the revolt and the war in the North
Theon and Yara decide to go somewhere for some reason, and Euron, as the new king of the Iron Islands, decides to do something crazy (not really a big fan of their story lines)
Arya has to kill somebody that doesn't seem to deserve it (some random nobody), but the experience is her impetus to break off from the faceless men and return to Westeros
The Iron Bank turns out to be the Faceless Men's best customers, it's how they deal with deadbeats, and maybe they give Arya an assignment in Westeros (Stannis owes them money, but is dead already, the Lannisters owe them money, but I think will die other ways, so, I'll say one of the Tyrells, who probably also owe them money)