I noticed two remarkable things watching the episodes...
1. When Amon takes someone's bending away, he only puts a dumb on the head, but whenAang takes someone's bending away, he puts a dumb on the head and the heart. Could that be a significant difference for those who also remember what the giant turtle said?
"The true mind can weather all lies and illusions without being lost. The true heart can touch the poison of hatred without being harmed. From beginningless time, darkness thrives in the void, but always yields to purifying light."
I think that Amon doesn't 'use' his heart, that he doensn't care about anything or anyone but conquering the world, and that Korra'll find out that's his weakness and maybe the only way to defeat him? Could it be, like the lion turtle warned, that when you energybend the wrong way, your soul get's damaged? Maybe that happened to Amon, and so far he only could benefit from it, but (maybe) Korra'll find out and use it against him?
2. But i'm not sure of this one: When Aang took away the bending powers of Yukone, was his son (Tarrlok) already born? Because otherwise, people mabye lose their bending, but they still can pass it over to their children. That would mean that Amon's work will never be over... Or am i wrong?