First of all, I love that ASOIAF is probably the least magical fantasy series I have read and it’s great because you cannot count on magic as deus ex machina every time something bad happens, and even if magic does intervene, it always comes with a twist. But magic does play an important part in the series and judging its evolution in the books, it will become more and more significant.
Magic is the force that will either be the salvation of the seven kingdoms or their destruction. Or both. Magic could save them from the cold winter, but a force that does not depend on the system of intrigues and manpower will most likely be the destruction of the political and military status quo.
The story is cleverly constructed in a way that whether you want it or not, you become so involved in the political fight, that you almost forget about the threat of the Others. And the victors of the political war WILL HAVE TO deal with this problem, otherwise everyone and everything will perish. And the fight with the Others will be won by magic, not by Littlefinger’s intrigues, Varys’ plots, Lannister armies or political marriages. Magical characters will play a very important role in the end.
And I personally believe Daenerys will play a key role in the battle against the Others and I base my belief on one of Daenerys’ dreams:
"That night she dreamt she was Rhaegar, riding to the Trident. But she was mounted on a dragon, not a horse. When she saw the Usurper’s rebel host across the river they were armored all in ice, but she bathed them in dragonfire and they melted away like dew and turned the Trident into a torrent."
It started with a knock on the door. Outside were two policemen, hats in their hands. “Are you mr Hillsbury?” One of them asked and then said, when he had gotten confirmation that this was indeed mr Hillsbury, in an apologetic, and rather distant tone if truth was to be told: “I am truly sorry, but I have come to inform you that your son has been involved in an accident”
"Now, why is the floor getting larger?" Mr Hillsbury managed to think before the darkness took hold of him.