CO has 3 billion or thereabouts, and probably better credit. AMR has 6 billion in the bank and probably better credit. . Hell, United has 5 billion, and even NW has 3 billion. What Delta has does not matter, since that dog did not hunt the last time.
Were I to swag at this, it's still not going to be a transaction that puts 320pilot into a 777 out of ORD. Think about NW for a second--Parker axes MEM (thereby satisfying the "reducing capacity" fetish), keeps DTW/MSP for that missing chunk in the middle of the country, and gets his hands on China and the Pacific. Some degree of fleet commonality.
UAL is not Dougweiser's style--they did not get hit hard enough on the cost side in bankruptcy. The folks running CO don't strike me as suicidal, AA is a nonstarter for any number of reasons, DL was asked and answered already.
I don't think Alaska or Frontier do much for the network, but it's not like it's a winner now.
If I had to guess (with public information, anyway), I'd say it's either a breakup of LCC or something LCC/NWA-ish. Private insights, of course, may be different.
Oh, and the mother of all pissing contests for seniority integration (including, but not limited to, an instant Nicolau implementation, ALPA stays on the property, and then everyone does it all over again in a few years).