Well, it looks like I left out quite a few cities that are served only from CMH with America West...lol.
It's true, Chicago Midway and New York LaGuardia have service only to Columbus with America West. However, for example, a passenger in Phoenix wishing to travel to New York City can find a nonstop to JFK, the passenger would not have to connect through CMH to get to New York.
DesertJets: according to America West's website, the Toronto flights will be operated by Mesa CRJ's, probably those that once flew between CMH and EWR. They will most likely change to ERJ's once complete integration has been accomplished.
AmericaWest: though the CRJ's will leave Columbus, they will be replaced with ERJ-145's. Since 12 of them will be based in Columbus instead of Mesa's previous 9, it is allowing for the expansion that is taking place. Also, it will allow America West to focus operations out West, and allow Chautauqua to focus on the East/Midwest.
Mbird139: currently work is being done on expanding Port Columbus' Concourse C. 5 gates will be added to the concourse and work should be completed by the summer of 2002. However, Delta has already announced they will lease four of those gates, and it is most likely that the 5th gate will go to Southwest. Delta will move from it's current two gates in Concourse C to the four new gates, leaving only 2 free gates in the entire airport. Two new gates are also being added to Concourse A, though I'm not sure who will lease them. America West operates from Concourse B, and utilizes gates B1, B2, B4, B5, B6, B7, B8, and B9. With American's buyout of TWA, their operations at gate B3 will be consolidated to American's current 3 gates. This allow America West to go ahead and takeover B3. Port Columbus also already has a master plan for the next 100 years. Since the current terminal complex is at capacity, a new terminal will be built along International Gateway, the airport's main road. The new terminal will be built 8 gates at a time as demand warrants.
JetService: I'm really hoping that America West Express starts service between Columbus and Fort Wayne, as well as Toledo, for several reasons. First, it would provide regional feed into the America West system from Columbus, which is currently almost non-existant. Secondly, it would provide a low-fare alternative for FWA, and a second one for TOL. Both airport are underserved, especially TOL, I think passengers would support a new choice in air service, especially with the possible loss of Comair. Service to TOL and FWA would allow Continental passengers to take advantage of codeshare flights though CMH. TOL and FWA recently lost Continental Express service to CLE. So for example, a Continental frequent flier member can fly from Houston to Columbus on Continental, then take advantage of an America West codeshare flight to get to his final destination in Fort Wayne. Also, connecting through CMH would provide a convinient alternative to large congested hubs like Chicago and Detroit. Walking distance from B9 to B1 is about 5 minutes, and CMH's two parallel runways can handle simultaneous landings.
CactusA319: you're probably correct about the ERJ's taking over CRJ routes in August. I know CMH-ATL starts Aug. 1 with ERJ's, but I'm not aware of which other cities that will get ERJ's before September.