Alaska dismissed this a month or so ago. Alaska is a great airline and would be a good partner with AWA/US. The biggest difficulty I see is fleet incompatability. Alaska is all Boeing (including MD80), while AWA/US is going away from Boeing. Wouldn't this be like the hodgepodge that occurred when US bought PSA and got MD80's as part of the deal?
Fleetwise, Frontier would make more sense, but that would completely alienate any ties with United. The best thing is for AWA and US to spend a year or two integrating before worrying about merging with anyone else.
