The lies concerned certain gifts that were given by Alaskan business interests that he failed to disclose. Because it's generally not very well reported, I'll just say that there was no allegation that Stevens actually did anything in return for them (something implied when the papers claim he was convicted of "corruption").
The trial involved a fair amount of controversy, including an element of prosecutorial incompetence if not outright misconduct. Accordingly, Stevens is fighting on in bid for reelection. He will likely remain free pending appeal.
Stevens certainly does have a right to his appeal, and may very well win. However, the people of Alaska are entitled to honest government and to rest assured that they have it. Stevens should have stepped aside given his indictment and let someone else carry the flag for the Republican Party, which has been damaged as a multitude of GOP Congressman have now been convicted for not fulfilling their ethical duties as Members of Congress.
The Washington Post's editorial captures an important, larger lesson from the Stevens case:
There is a larger lesson in the Stevens prosecution, which is the sense of entitlement to which public officials can fall prey and, perhaps among the most powerful, a sense of imperviousness to the ordinary rules. After all, they may tell themselves, they work long hours for far less money than they could make in the private sector. After all, they have done so much for their constituents... This is a mind-set that has been on sad display all too often in Washington in recent years, and, in truth, it is something that not even the most stringent ethics laws can fully protect against... Mr. Stevens worked to give so much to his state, but he forgot the most important duty he owed its citizens: honest service.