Of course, the one option which the administration is foolishly overlooking is putting the Guantanamo detainees on trial in US criminal courts. That would more than meet the criteria of the UCMJ and the Geneva Accords, under which they could be tried as terrorists rather than as legitimate combatants. As demonstrated in other cases, American juries would be unlikely to be terribly sympathetic, but it appears that the associated publicity and potential difficulty of presenting the cases in a regular court are more than the administration wants to take on.
Taken along with the 2004 decision from the Supreme Court which determined that the GITMO detainees could not be held indefinitely without trial, this ruling puts considerable pressure on the administration to go further in resolving the status of those still being held. Many detainees have already been returned to their home countries, where some immediately resumed their terrorist activities. Those who remain are likely the most dangerous of the lot, but they're a lot less dangerous to the United States if they're in a faraway country and that would at least be some progress. It might be a good idea to keep a few for show trials under US justice and just dump the rest at this point.