Buying a debt-laden airline and trimming the fat + increasing yield while getting leverage on partners and expanding logistic capacity sounds like the ultimate Amazon move right now. Probably not AA, but I don't know... Southwest?
I'd be disappointed if it was Southwest, I always have a great experience with them. Wouldn't surprise me if they went with a budget airline and used the extra capacity that people don't fill with overpriced baggage to ship Prime products. It sounds like a nightmare to coordinate but I'm sure they could do it.