Here is some stuff I found interesting from Charlie Cook's Column:
Few doubt there is an undertow for the GOP this year. The question is how strong it is and how many Republican candidates will be pulled under. The fact that a Democratic candidate viewed as mediocre at best is going into this election in a dead heat in a Republican-leaning district should scare the life out of any Republican.
There is no doubt in my mind that there will be a few Republicans who survive that many thought were dead meat, while others, who haven't even been seen as especially vulnerable, will lose.