The US Census figures for Pennsylvania are out and public. Philadelphia and the four "Collar Counties" increased their population. Philadelphia had a small increase (less than 1%) of 8500 people, Delaware County increased by 1.3% and the other 3 counties (Chester, Montgomery and Bucks) increased by more then that. Philadelphia is still the 5th largest city, ahead of Phoenix AZ, but that's another diary.
While the Philadelphia area held its own, The Greater Pittsburgh area lost people so, according to common sense, the Congressional district eliminated in PA should be out west. However, the Republicans controll both chambers of the state legislature and will probably end up messing with every district, both to even up the population as required and to try to protect Republican incumbents in any way they can.
Chaka Fattah's 2nd Cong. District was the third smallest district in Pennsylvania, so the area of the 2nd CD will probably be expanded to encompass more of the city in geographical area. This will be done either by expanding it into what is currently the 13th (Allyson Schwartz) or the 1st (Bob Brady) or some combination of both. I suspect this will cause Bob Brady's district to move west, encompassing more of Delaware County.
As evidence for this possibility, let me tell you about Margo Davidson. She's a freshperson state rep and she's a Democrat. After the 2008 elections, Mario Civera (the long term Repub.) vacated his 164th seat by being elected to Delaware County Council. Maybe he was reading the handwriting on the wall. In 2010, the district which encompasses parts of Upper Darby and the boroughs of East Lansdowne and Millbourne, elected Margo Davidson a Democrat, even though the Pennsylvania Democratic Party lost the State House. Of course, Pat Meehan lives in Drexel Hill which is also in Upper Darby Township.
One more possibility is that the 7th district will encompass more of Chester and Montgomery county. Which brings Gerlach and Schwartz into play. Keep your eyes on Pennsylvania, for electoral shenanigans all around.