Hello everyone, haven't been posting for a time, but I've been reading the books again, waiting for the third season HBO, a couple quick thoughts:
A) Trees are now scarier than dragons
I think the 'dark terrible things' that lie in the deepest crypts of Winterfell is not a dragon fueled hot water heater, but the same sort of weirwood root chamber where Bran found the Three-Eyed Crow. Bran is destined for the tree, not the one he's at beyond the wall, but the godswood tree of Winterfell. "There must always be a Stark in Winterfell." I think every few generations a Stark is born a greenseer and given to the tree to watch over the family. How else do you explain ruling half a continent for 10,000 years? Also, this isn't the first such root chamber we've been shown. In Storm when Arya is taken by the Brotherhood Without Banners to meet Dondarrion and judge Sandor Clegane, she describes that cave as being full of huge white roots. Someone calls it an old deep hidden place. Thoros can't see anything in his flames just like at High Heart. Dondarrion is sitting on some naturally formed from the roots chair/seat and walks down a kind of root stairway to accuse Clegane. Almost a mirror image of what's described in Dance.
B) Sea Dragons? YEAH BABY!
In Feast the Ironborn hold the kingsmoot at their most sacred place, the Grey King's hall, under the bones of Nagga on Old Wyk. Asha's version of that legend, complete with 'living fire' references, made it seem plain to me that Nagga was a sea dragon.