Thank you very much forr al the replies! there are some interesting considerations for sure...but let me clarify a few things.
When I say that LOTR charachters are black/white i do not mean that they are FLAT (they are not, and I loved the book by the way), but that ultimately you have Elfs (super cool, super smart and attractive, besides), Men (like us), Dwarfs (a little like your grumpy, hairy great-aunt) who are threatened by Orcs (ugly, smelly, stupid, cruel) led by an EVIL/Satanic lord. The whole book builds up to the final showdown, to the GOOD vs EVIL BATTLE that settles everything, and I would like to know how many of you were actually rooting for Sauron, in the end.
ASOIAF has been - so far - a story of conflicts for power in which you had good reasons to support more than one party involved, if you wanted to. And then you have the Others. As of now, the only concrete consequences of their presence is to force the wildlings to find a way to cross the wall; the rest of the world seems rather unaffected by their existence. However, the clues we have from the books suggest that their role will become greater and greater. If not, this would be quite anti-climatic. If they do have a huge role in the next books, the risk is IMO that their arrival will pretty much reset the current equilibrium and alliances and change the book into: ok, let's put our armies together and fight the battle of Men VS Others. Ok, not everyone will join in (as Dwarfes and Elves in LOTR), but in the end that conflict will be the ultimate cause of the new equilibrium in Westeroes/Essos.
IF this happens:
- most of what happened so far is relevant only to decide who is going to fight the Others and his strenght at that time
- most of what happens after the battle will be decided within the arc the battle itself
- it will be really hard to root for the Others, even though Men aere selfish and greedy, and do not respect trees and animals enough -- OK but do we deserve to be exterminated for that? See Great Flood
So all that was build until now will have a moderate relevance in the end, and we will be reading about a great battle where we all (almost all) agree who should win, that will be the ultimate cause of the story ending.
That said, I TRUST Mr. GRRM will do a great job and I look forward to read it.
your prediction of not homogeneous Others could be indeed an interesting path!