The most compelling theory I have seen for how the series will go is in this blog:
http://gameofthronesandnorsemythology.b ... -fire.html
It may be a megaspoiler and sometimes I regret reading it because I think it is largely how things will go. Directionaly accurate, not 100%.
The Jamie chapter also blew my mind: http://gameofthronesandnorsemythology.b ... f-war.html