What will happen to ex-US hubs if the mergers go through? Obviously they'll have to sacrifice Washington to appease the law makers, but it seems almost impractical for UA to operate PHL, PIT, CLT and LGA at their current pace on top of the already existing UA hubs. Which one(s) will they cut back on?

No, they won't cut back any of the hubs. That is the point of the whole merger. UA's current hubs are all midwest and west coast situated. Due the heavily populated geography of the east coast, having hubs in PIT, PHL and CLT work very well. Ultimately UAL MAY drop one of these but for now this heavy hub dominance in the east is what drew UAL to grap USAirways in the first place. UAL could get you from the west to the east but once east, if business required you to travel within the east, UAL wasn't likely to get the business.

I can possibly see some consoidation in the PHL/EWR/JFK/LGA and maybe BOS operation and IAD/BWI (maybe moving all of BWI to IAD or vice-versa). I can also see some south america flights being moved to CLT from MIA.

I doubt UA will move its MIA flights to S. America to CLT. It won´t work!!! MIA is a key market to S.America and if UA did that, I´ll bet DL would jump in MIA.

Sorry, but CLT to S.America has a very slim chance!!

CLT to South America? I doubt it.

They would have said the same about flights to South America from Dallas and Atlanta had American and Delta not dumped 500+ flights a day into each airport.

It would be insanely stupid if UA dumped the US hub and route structure on the east coast. Why spend the money the acquire an airline to then completely dismantle the route system. Look at the AirCal and PSA mergers with AA and US, what of those airlines route structures are left in the current route maps for American and USAir? The more I think about it Pittsburgh is a something that I think United would want to keep. The airport can expand fairly readily, I think it can support double or triple independant IFR arrivals, it has a big terminal with tons of space. United is boosting Charlotte as a competitor to Atlanta. It is a rapidly growing city with a variety of industry in the region. It is a good n/s connector, and some flights to Latin America would not be out of the question (see above). Baltimore is not much of US hub anymore, most ops are either express or MetroJet. Philly is at some risk because I don't really see how it fits in. Connections in the northeast could just as well be made at Pittsburgh or Dulles. And the European flights would likely be transfered to ORD, CLT, or IAD.

However any of this is in the long-term... 5 years before major changes would be noticable, with the exception of a Charlotte build-up. It is fun to speculate about this, but I still doubt more and more that this will go through.

United will not keep what isn't profitable.. and even marginal profitable routes are being questioned.

Chicago - Madison
Chicago - Milwaukee
Denver - Sioux Falls

Must I go on? Many cities will see service moved around under the UAL banner....