pretty significant news broke at the end of business today. AA withdrew their support for the ORD expansion plan because they claim that UA and the mayor's office snuck a "secret provision" into the deal at the last minute that gave UA additional gates (IIRC, AA claims this figure is five gates).
the mayor says he'll go forward with the plan,
with or without AA's support.
Emanuel vows to push ahead on $8.5B O'Hare expansion as American Airlines decries 'secret deal' - Chicago Tribune
all in all, not a great week for UA's rivals politically thus far. DL's relationship with georgia's state government isn't exactly peachy, and now this news about AA from ORD.