It is my understanding that with less hub-feed flying, the mainline assets will primarily be redeployed to the 3 focus cities (LGA/DCA/BOS) where we will see a mixture of new routes and Express equipment being upgraded to mainline. As has been proven with JetBlue, mainline flights are justified on routes such as LGA-BUF/ROC/SYR - if the fares are reasonable.
I would not expect to see cities which are close to being "mainline express" gain any mainline A/C. ORF, RIC, etc. can very easily have no mainline on the Sept. schedule and have MidAtlantic/Express only, thus enabling the company to classify these stations as mainline express and reduce costs. I understand that the stations that are in extreme danger are ILM, GSO, EWR, & PNS.
If the company is successful with the "transformation plan," expect to see a continued increase in Carribbean flying, as well as shifting some assets to more transcon/west coast markets. Do not be suprised to see the opening of some new mid-con/west coast stations. With just 2-3 flights/day, these stations can be mainline express as well.
Unfortunately, this is the sad reality of US Airways today.