We've had some delays going through Philly as well. Some late takeoffs due to having to de-ice the plane. We find that connection times now with US Air are really tight and we often have to almost run to get to our next gate. Not quite sure what the answer is. We have done carryon only to get to the connection as the flight was boarding. No Zone 2 luxury for us! Had to gate check our bags! Not happy! Good luck! All you can do is hope for the best!