I don’t think that it was ethical for Assange to leak the Manning documents. Although it didn’t cause any damage to the U.S. strategically, the report of the leak stated that the leak could have done some serious damage to non-US soldiers, and I also don’t see any good that came from leaking the files which led to the arrest of both Manning and Assange.
Given manning’s severe sentencing, it seems likely that Assange will also be given a harsh sentence if extradited to the US. I think it is ethical for him to be arrested and extradited over charges stemming from an investigation that was dropped. I don’t think that he should be charged as harshly as Manning but if he did the crime he should have to do the time. Before he leaked the documents, I am sure he knew what he was getting himself into.
Was it ethical for Ecuador to shelter him for the past 7 years? Was it ethical for Ecuador to end his asylum now? Depending on the reason why Ecuador gave him asylum, sure I think it was ethical if it was for a good reason. In the MSNDC talk about Julian Assange, they said that Ecuador ended his asylum because of his bad behavior. I also think that is ethical because if he was causing the Ecuador Embassy harm, why would they keep him?