I refer back to my post and suggestion as part of an earlier Poll. I believe that if US and UA merge, parts of UA (and now, also possibly US) will be sold off to other airlines as part of the deal. If this is done by intelligent resources, a "lean and mean" combined carrier could result. This would seem to negate a lot of the naysayers doomsday predictions that the merger would create a "bloated elephant" of 2 less than stellar airlines and result in a single huge disaster (i.e., 1 Bad + 1 Bad = 2 Bad). One of the biggest ? IMO is what will be the tradeoff between IAD and PHL. IAD has better general Yields, but only over 1/2 of the PHL Domestic O&D. U.S. carrier International O&D is very close to equal (near 3M each). One major item, which could easily offset the domestic yield differences in favor of PHL, is the Cost Per Enplaned Passenger. At PHL it's approx. $8, at CLT only $2-$3, but at IAD a relatively gigantic, near $22 ! This also illustrates the potential costly endeavor in switching major Hub services to IAD from CLT. Based on this, I don't think it's unreasonable to predict that PHL will survive and grow, especially since the airport is now finally in firm "growth mode", and IAD will be downsized, or the routes and appropriate slots, sold to someone like AA. I feel there would be government pressure for some U.S. carrier to retain at least a significant portion of the IAD international routes. Also, similar to DL at ATL, if Parker is the merged CEO, he would likely favor PHL over IAD for the emotional/ego reason that he has been/is able to influence decision making - especially with the new city administration.
Another sticky situation would be SFO versus PHX. IMO, because SFO is the ideal Asian gateway, both location wise and environmentally (not Hot and High = Less MTOW), it would supplant PHX as a Hub. PHX would then be either Focused or AW would be sold as a Regional carrier - much like it's former life to someone like DL/NW.
Regardless of whether US merges with another Legacy, or stands alone, it will have to somehow optimize it's route structure relatively quicklyto offset the current economic down turn. A major tool to accomplish that is a significant increase in high yield international routes.
Unfortunately, US is now caught in a situation that, because of lack of suitable aircraft, it will loose that opportunity for the (now) all important 2008 Trans-Atlantic/Asia season. Endeavors, such as "no more free Peanuts", will essentially be "Peanuts" to the bottom line, potentially just irritate customers and fuel the already mediocre service reputation of the airline. Higher fares to support better competitive service is one of the key offsets to surviving this major downturn, IMO.