I think a lot of the North Lord's will just stay out of it. They have no love for the Bolton's and will probably wait and see which way things are going rather than pick and choose. Heck if the whole thing is based loosely on the War of the Roses then that would be pretty accurate, especially for the 3rd stages of the War of the Roses, which by this point is actually quite similar to the current setup in GoT.
Seen some crazy Arya theories running around. Some are that Jaqen H'ghar was pretending to be Arya in the last episode as a test of the waif's true intentions. Based on things like Arya not having needle and having all that gold. I would be surprised as it would make little sense but who knows with GoT these days.
Also wtf is up with the Waif. She's supposed to be all faceless man, no motives for killing but she clearly has some ridiculous grudge thing going on with Arya.
I didn't much care for the Ayra and the faceless men story arc so I'm glad that's taking a different path.
Thing is they just wasted what, 2 seasons, with that story arc if they don't follow it through and for absolutely no obvious purpose. I suspect they will continue that one just because dropping it now would have been a massive waste of time.