I've noticed Martin's comments about realizing he can pull off a shocking twist for a character.
I've read many suggestions both at the Tower and Censoros.
Here's my call: The twist is that Sweetrobin is Littlefinger's son by Lysa.
This should work in relation to Martin's comments about the twist involving three or four characters (Sansa, Sweetrobin, Littlefinger & Lysa) and to be something "organically from the writing" (in fact, organically gets a double meaning!)
Now if George is a brave boy and does indeed fight THE WINDS OF WINTER into being published next year we'll see if there's a shocking twist for us all to enjoy. HOWEVER Martin also stated that the twist. *can't* exist in the show due to said character receiving a twist can't receive it in the show (so either the show version is dead, or has a different storyline). And this irks me as I really like the idea of Littlefinger being Sweetrobin's dad.
Which leaves... too many options: Jaime and Bronn are doing different things. A whole host of book characters don't even exist on the show. Lady Stoneheart, Jhalabar Xho... maybe the twist is that Lady Stoneheart isn't undead after all, just having a really bad case of the flu. HOWEVER HOWEVER, the comment *could* potentially include Season 5 (if George knows the general outline of the episodes) and as such.. Sansa and Littlefinger are leaving the Vale, while the newly released teaser chapter shows them firmly entrenched in the Vale. Weak, yes, and merely speculation, indeed. We can only wait some more and see.
Fortunately there's PILLARS OF ETERNITY, oh my it is such a splendid adventure, and I can't imagine anything else but it becoming my new favorite interactive fantasy, bumping venerable BALDUR'S GATE to the second spot. And then, of course, there's STAR WARS: THE FORCE AWAKENS, with a remarkably quiet period right now soon to be shattered into a frenzied hype, most likely. And, of course, one page at a time, probably even slower than George writing, I'm getting through THE RED KNIGHT, with Django Wexler's THE THOUSAND NAMES up next in the queue. I'm considering simply giving up on Brandon Sanderson's THE WAY OF KINGS, as I did R.A. Salvatore's THE COMPANIONS. While the latter is just horribly written tripe, the former just utterly fails to grab me, well written and lore-soaked though it is.
Oh, Sansa Stark. I really have no clue where your story is headed. I have suspicions, but they kind of don't match just two more books in the series.