The Citadel is an archive of information for George R.R. Martin's A Song of Ice and Fire.
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I too picked up a few things in talking with him...
In no particular order:
We won't see any (or very little) of Rickon in AFfC.
I was talking with george and the dude from FFG [Fantasy Flight Games] who does the card game, and George asked the FFG guy how he was going to balance the power of the families (Stark, Lannister, Greyjoy, etc) once the dragons are full grown. He said something like "once dany lands in westeros with full grown dragons, they are gonna kickass all over the place" (paraphrasing - it was something more like "they will be tougher than anything we've seen since Aegon the Conquorer.")
We probably won't get the POV from an Other, but we will find out more about them (history, motives, etc.)
Oh, I also asked George if he could say what new map(s) there will be in AFfC. He answered the Free Cities.
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