In Return to Ravnica all ten gilds will be covered in the first two blocks, so the question is: what will the last block cover? I think the most dramatic thing for a city of Gilds at war to do is simple.
Alliances.
Two gilds forming one to double their power, with the intent of finally destroying the other 8 gilds. There would be plenty of back stabbing and empty promises, but that's half the fun. Here are my piks for the gild "parings";
Marshal Law: Boros/Azorius
They rule this town, from the stinging gutters to the shining roof tops, and the low life's that crawl through the streets have finally gone too far. They will get in line or be