In the Senate, Landrieu (D-LA) and Pryor (D-AR) will vulnerable no matter what. Baucus (D-MT), Begich (D-AK), Frankin (DFL-MN), Hagan (D-NC), Johnson (D-SD), Shaheen (D-NH), M. Udall (D-CO), and Warner (D-VA) depend largely on how the economy is doing. Collins (RINO-ME) would be replaced by Democrat if she doesn't run again. Graham (R-SC) might get TP'd and then have the Democrats win, since I seriously doubt a non-kooky person would get into a primary fight with Graham. (Altho that's probably why he's in such a boil over Rice right now so as to avoid a serious primary challenge.) If Rockefeller (D-WV) retires, his seat is a likely GOP pickup, but if he runs, he should be able to keep it. Anyway, I expect the GOP to gain anywhere from 1 to 9 seats in the Senate in 2014, with 3 as the most likely number, which isn't enough to take the Senate.
There is no way that Warner will lose Virginia, he's so popular in that state that he's very much in live boy/dead girl territory.
I don't have any first hand experience with any of the others, but Pryor got 80% of the vote in 2008. He wasn't even challenged by a Republican, the Green party got the other 20% of the vote.
