So who's going to rule Winterfell, Jon or Sansa? I would love to see Jon legitimised, but Tommen would need convincing. I guess Sansa could make peace with Tommen, I mean he's not Joffrey...
Amazing episode, maybe the best ever.
I have a feeling Jon doesn't really want to sit as lord of winterfell. I think he's done holding titles of command. Bran would be the heir at this point, assuming he ever makes it back, but he's probably even less likely to want the job than Jon, now that he's the one eyed raven. So my bet is on Sansa, both because the others don't want the job, and because it would fit her character arc.
The question of what will happen with the Lannisters is an interesting one. The Boltons were in Winterfell by royal decree, and House Stark is still in revolt against the crown; it's just that for a while there, nobody realized there was any House Stark left.
So it's conceivable that Tommen could send the Lannister army north again. If it were Cersei's decision, she probably would, both because she blames Sansa for Joffrey's death and because littlefinger has now betrayed the Lannisters. But Tommen, crazy as he is, isn't his brother, or his grandfather, or his mother, and i doubt he has the stomach for re-launching the war. And, it's not the way the plot is going.
Plus, you'd have to figure that the other northern houses would again back the Starks, now that the Boltons are dead and the Vale has sided with the Starks. So would the Lannisters (or the producers) really want to reprise the season 3 conflict but without Rob/Joffrey/Tywin? I think they'll go in other directions-it's time for white walkers in the north and Denarys in the south.