My 'predictions'
Oregon: Merkley quitting makes it kinda competitive, but unless they run Smith, it'll probably remain in Democratic hands.
Montana: Leans Pickup. Baucus is very unpopular and Juneau is too liberal.
Wyoming: Safe, unless Enzi quits, where Frudenthal might run.
Idaho: Safe
Colorado: Udall's very visible - he should be fine.
New Mexico: Probable retention. Martinez or Wilson might make it kinda competitive, but maybe not.
Alaska: Tossup. Palin's very polarising, but Alaska is a very red state.
South Dakota: With Johnson running again, he should be favoured.
Nebraska: Safe
Kansas: Safe, unless Roberts loses his primary and Selebius runs.
Oklahoma: Semi-interesting, but it'll most likely remain in Republican hands.
Texas: Semi-interesting, but the Democrats need a really strong candidate.
Minnesota: Probably leans Democratic, but Pawlenty is probably more of a threat than Coleman.
Iowa: Safe unless the country turns sour, which it doesn't appear to be doing.
Illinois: Despite Durbin's retirement, I doubt they'll hand over both seats to the Republicans, plus they have a very strong candidate here.
Michigan: Toss-up. Republicans have a stronger bench here, but it also leans blue.
Arkansas: Leans Democratic, Pryor isn't an exceptionally strong candidate, but you let Lincoln pull off an upset (iirc?) and Pryor also has a famous last-name.
Louisiana: Landrieu would probably lose in real life, but given the identity of the person doing the TL, she probably will eek out another win
Mississippi: Cochran might retire, which could maybe make it interesting, but it's not likely.
Alabama: Easy win.
Georgia: Competitive on paper, but the Democrats don't have strong candidates.
South Carolina: ditto.
Tennessee: The Democrats won the other seat, I'm not sure if the state will elect 2.
North Carolina: Leans Hagan, but will be competitive if the Republicans find a strong candidate.
Virginia: Warner is probably unbeatable, even against McDonnell.
Delaware: Safe.
New Jersey: Depends on LoBiondio's primary. If he wins it, he's the favourite, otherwise Democratic gain.
Rhode Island: Safe
Massachusetts: Safe
New Hampshire: Interesting, but Shaheen will probably hang on.