HBO - Game of Thrones SPOILERS INSIDE. you have been warned

[strife]

The only thing I had a question about was John going further North at the end. He was sentenced to be in the Night's Watch. Granted him and Tormund were both wearing the black, so maybe they were escorting the free folk back home?  

Also I see GRRM's hand in teasing everyone along with John and then giving us Bran the Broken as the King.

I'm lost on why to even have the nights watch now.  What are they protecting the "south" from?  It made sense before with the white walkers and the wildlings being the enemy.  Now the Wildlings are friendly and even part of the nights watch, and the white walkers are gone.... so what's the point?