The common themes in these discussions seem to be we cannot simply turn them loose or return them to the countries where they were arrested because some of them may be "really bad men." A few might possibly even return to their former mission involving terrorism. To this let me quote a line from Dick Cheney himself, "So."
So what? Currently in the world there are tens of thousands of people who may advocate and or even be working to advance acts of terror against The United States. What possible significant difference could the few individuals being held in Cuba add to this vast pool of current and future actors?
The Republican congressional leaders have bandied about some report that suggests that one former detainee who was released has even become an al-Qaida leader somewhere. Do you suppose that position of leadership might somehow be vacant if this guy was still at Guantanamo?
I say "throw these fish back into the ocean" and get on with correcting the massive damage the Bush administration has done to our world reputation.