It was almost two years ago that there was a sudden flurry of articles in military professional pubs voicing second thoughts about the effectiveness of Gitmo. With the shift we've had in Congress, and presidential elections rushing fast upon us, I believe there's a lot more pointed discussion of the issue coming....

...here's some of the older material:

From Joint Forces Quarterly: Guantanamo Bay: Undermining the Global War on Terrorism
...In addition to undermining the rule of law, the consequence of the policy at Guantanamo has been to fuel global anti-Americanism, which undermines U.S. influence and effectiveness, degrades the domestic support base, and denies the United States the moral high ground it needs to promote international human rights. It appears that these costs have far outweighed the operational benefits that the detainee operations have generated...
From Parameters: Six Floors of Detainee Operations in the Post 9/11 World
...There is good reason for the international community to agree upon more understandable and more stringent measures against unlawful combatants and terrorists in order to deter hostile forces from adopting such tactics. But we must not legitimize inhumane measures and debase ourselves by adopting anything like the tactics of the common enemies of mankind...
From Military Review: Defining Success at Guantanamo Bay: By What Measure?
...Success in the struggle against terrorism will be measured in generations. When future strategists look back on the early years of this decade, they will not judge Camp Delta on the relative value of intelligence reports but on humanitarian issues, how detainees were treated, the legitimacy of the trial process, whether laws reflected evolving definitions of “combatants”, and how detainees were ultimately dealt with when America dismantled terrorist groups. As we discover what the law will not allow, serious action to define what is permissible will follow. Justice—evidenced by whether criminal defendants were successfully defended or prosecuted, acquitted or convicted, fairly sentenced and safely incarcerated or repatriated—will be the enduring legacy of America’s actions at Guantanamo...