If they plan on keeping a partnership with DL, then I think Atlanta is out. They have avoided Delta Hubs so far.

ORD MUST be next on their list. Hub for 2 of the 3 US airlines. The problem is where do you put it. I imagine it would have to be enormous. I actually think they probably need two there.

I like the idea of CLT. Losing the US club there will be huge.

I think that MIA and EWR, and IAH are the next no brainers.

I think people are listing their own persona wish lists, which is fine, but I think the above airports would serve the most customers and fit into a cogent business plan for AMEX.

That being said, the selfish pick for me is ORD.