With the CO and UA merger, which CO hub will loose more. Since UA already closed a CLE hub in 1986 they will probably do it again unless somwe of the CO people stick up for CLE. Logic would say that with ORD congestion
CLE will be kept, but logic is not always used. It will be about profit potential.

Houston (IAH) will loose the headquarters. Just a question, how is it working at DL, is the NW headquarters still pretty active, IAH may loose some flights based on it;s location. If you are going to Seattle or anywhere in the Northwest it would be a more direct routing to go through ORD or DEN then IAH.
I really do not see alot of changes at EWR. They do compete with IAD for several international flights, could cut on the IAD side.