I suspect that AA may not be paying much for these 777-300s and that may help explain why AA has not secured financing for them. Perhaps Boeing will lease them to AA for a nominal sum.
Why would Boeing be so generous? Today, Boeing announced yet another delay in the expected delivery date of the first 787-9 to early 2014 from late 2013. AA is not mentioned in this WSJ article (linked below) but AA's expected 42 787-9s have been subjected to multiple delays since AA first announced the order, and no doubt AA has sought compensation for that delay (as have other airlines). Perhaps some very cheap rental of some 777-300s is part of Boeing's compensation package?
http://online.wsj.com/article/SB10001424052970203687504577000213541613988.html
If you get the abbreviated version of the story (telling you to subscribe to read it), go to Google News and search for it there - that's how I got the full version of the story.