Bryan Whitman, a Pentagon spokesman, said it has always been the Defense Department’s position that detainees could be held as enemy combatants even after acquittal at military commissions or after serving a prison sentence. “That’s always been on our minds in terms of a scenario we could face,” he said. “He will serve his time for the conviction and then he will still be an enemy combatant, and as an enemy combatant the process for potential transfer or release will apply.”
– http://www.washingtonpost.com/wp-dyn/content/story/2008/08/09/ST2008080900876.htm

Having demolished the prestige and respect of the United States on the world stage, now they start worrying about how their actions will look?

Defense Department officials said there are concerns about the public perception of holding Hamdan after his prison term runs out, because it could label the military commissions a “show process” with no meaning to its sentences. They also worry about possible precedents that could be set in U.S. courts if Hamdan’s attorneys immediately file a habeas corpus petition seeking his release in five months. Hamdan previously won a Supreme Court case that invalidated the Bush administration’s earlier military commissions procedures. – ibid

I almost hope they do decide to detain him and Hamdan’s attorneys file a habeas corpus petition. The government would lose.