From the Washington Post:
Top 25 House races most likely to switch parties.
15. Pennsylvania's 10th district (D): This is among the quietest competitive races in the country. Rep. Chris Carney (D) hasn't done much to make himself vulnerable in his first two years in office but this northeastern Pennsylvania district leans strongly toward Republicans and GOP strategists expect John McCain and Sarah Palin to run well there. (Previous ranking: 16)
7. Pennsylvania's 11th district (D): Every cycle there is (at least) one incumbent who has done himself such grave political damage that reelection becomes an impossibility. It's looking increasingly likely that Rep. Paul Kanjorski (D) is that guy this year. (Previous ranking: 7)