Congressional Research Services – Congress’ think tank – has a significant report out discussing the legal issues associated with President Obama's executive order closing the detention facility at Guantanamo Bay (link available here). The report constitutes the most comprehensive publicly available treatment of the issues surrounding Gitmo closure yet offered by the United States government, so it merits careful study by anyone interested in American terrorism law.
(Full disclosure: I spent a summer during law school working for Congressional Research Services, and coauthored a paper with one of the attorneys who wrote this report).