Seriously though, this.
http://www.bbc.co.uk/news/world-us-canada-11623753
Why the delay on closure?
"Bipartisan opposition to the transfer of Guantanamo prisoners to the US has grown. Congress has not authorised funding for transfers and Mr Holder said in April 2010 that Guantanamo could not close without it."
From what I can tell, Congress was scared of pissing off their voters and wouldn't let the Obama Administration move the prisoners to U.S. soil. Both Republicans and Democrats blocked the move. Since this Obama has dropped the issue, and it looks like the prisoners are gonna be there for the long hall. I'd blame people in Congress (not to mention the American people themselves) for this before I'd blame Obama.