Here is some additional information about an issue air travelers should be concerned about, even thought it doesn't deal directly with PHL. The Consumer Traveler Web site has a longish post by writer Charles Leocha about the questionable proposal of US Airways and Delta to swap slots at Washington National and New York LaGuardia airports. As you may recall, the Department of Transportation rejected the airlines' first proposal, which would have given Delta more market control at LGA and US Airways more at DCA.
Their revised proposal revealed last week would have them sell slots -- which as you will see if you keep reading Leocha's post were obtained by the airlines at no cost -- to four smaller airlines. Left out of the deal was Southwest, which would like the chance to expand at LGA and possibly serve DCA. Read the Consumer Traveler article here.