If Vegas was setting lines on the amount of Gitmo detainees that will be released because the government's case against them is so weak, those lines may have just swung very heavily against the government. A ruling released this week by Judge Gladys Kessler said that the government's case to hold one of the Gitmo detainees was lacking in every facet. I have not read the opinion but this analysis by SCOTUSblog is clear and easy to understand. Apparently it looks like Judge Kessler gave the government a good deal of leeway in attempting to prove its case, including allowing the admission of hearsay evidence, but still found that the government did not have enough credible information to hold the detainee.
I think that this is certainly a bad sign for the government. The SCOTUSblog post says that 24 of the 29 cases heard by the D.C. District thus far have led to the release of the detainee. Now you have Judge Kessler allowing the government to cobble together a good case for detention in just about anyway it can and the information still is not enough. It looks like we are going to see the release of a good majority of these detainees because the government's case for detention against them is so weak.
Taking bets on the percentage of detainees that are granted release. Winner gets a blog shout out (which is a pretty big deal). As of now 83% of the case have resulted in release. I'm gonna put my money on 74%.