Quick, everyone! Get in the DeLorian! Its time to go Back to the Future! Seems like I can remember a time when US Airways and/or Piedmont had mainline flights like BOS-BUF, LGA-ORF, DCA-CHS, etc, etc.
Seems to me that when US Airways "Expressed" some mainline routes that should have been "Expressed" (BUF-ALB, ORF-CHS, MIA-EYW come to mind) that they also "Expressed" some routes which should not have been (i.e. to BOS/LGA/DCA).
Of course, the problems remain that BOS/NYC/DCA are being hit by LCC competition just as much as PHL is/will be. So while I think its going in the right direction, it is not the home run that this move would have been 10 years ago... (Of course 10 years ago, this hybid hub/point-to-point system was in place, so there would be no reason to "move" to it... and US Airways high costs and high fares helped LCC's to find these important markets, but I digress.)