Hi peanutgirl, a fellow nb'er here. We are also flying into PHL on US Airways with a 1 hour connection time. I am a bit nervous too as US Airways has three terminals, B/C which are connected and F which you have to take a shuttle to get too.
I am just crossing my fingers we connect through B or C, even though US Airways Express seems to connect through F. We are leaving out a Portland so a smaller plane.
Good Luck and happy travelling!