I talked with a friend at one of the manufacturers about this.... his take is AA is using Airbus as a whipping horse to get Boeing to move on the 797, and there's always more to the story with most of the Airbus orders and MOU's announced here this week. AA still seems to have decent access to financing. I suspect B6, AirAsiaX and Taca have some access, but that's probably not the case for the other carriers....
There's some truth to the opinion Boeing got shellacked this week, but Airbus has a habit of saving up orders for the Paris event, whereas Boeing tends not to flaunt their order book in the same way.
I'm still skeptical that AA would be talking seriously with Airbus after the liability lawsuits over AA857, but some people think the influence of IAG may be negating some of that negative karma. My opinion is that AA's still got enough bargaining power on their own that they don't need IAG to get to the next level of discounting.
The other discussion taking place that doesn't seem to be floating up as high on the rumor mill is talks on a 90-110 seater, which I see WT is alluding to above...
Now that RyanAir has taken the plunge with Comac, that's being seen a more viable option than it was two weeks ago. Again, I'm a skeptic there -- the leap of faith they took on Fokker 20 years ago shouldn't be forgotten, and Comac has yet to deliver anything yet.
Bombardier and Embraer have a much better history with AA, and also need the business. I think there's also a serious faux paux waiting with regard to labor relations for any US airline who buys a Chinese manufactured airframe. At least Airbus and Bombardier appear to be using unionized workers... no idea about Embraer. But Made in China?...
AA's got enough of a backlog of orders with Boeing that they could wait another few months to pull the trigger on a replacement. And I suspect that anywhere up to about 40% of the MOU aircraft announced this week will never actually be delivered, so if there's no movement from Boeing, AA could still get some favorable delivery positions for the A320neo.