Tyrion's talk with Cersei about how poison was such a better, more intelligent way to off someone was major foreshadowing. It will come back to bite him. Ros's death pose was lovely in a brutal sadistic way.
It will be interesting to see how Martin describes the Cranogmen. A Cranog was a common type of habitaion in Ireland about 1500 years ago. It was a man made island (obviously surrounded by water) common in the bogs of Ireland. Just like the 'Neck'.